package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

type bufReader struct {
	r   *bufio.Reader
	buf []byte
	i   int
}

var reader = &bufReader{
	bufio.NewReader(os.Stdin),
	make([]byte, 0),
	0,
}

func (r *bufReader) readLine() {
	if r.i < len(r.buf) {
		return
	}
	r.buf = make([]byte, 0)
	r.i = 0
	for {
		line, isPrefix, err := r.r.ReadLine()
		if err != nil {
			panic(err)
		}
		r.buf = append(r.buf, line...)
		if !isPrefix {
			break
		}
	}
}

func (r *bufReader) next() string {
	r.readLine()
	from := r.i
	for ; r.i < len(r.buf); r.i++ {
		if r.buf[r.i] == ' ' {
			break
		}
	}
	s := string(r.buf[from:r.i])
	r.i++
	return s
}

func (r *bufReader) nextLine() string {
	r.readLine()
	s := string(r.buf[r.i:])
	r.i = len(r.buf)
	return s
}

var writer = bufio.NewWriter(os.Stdout)

func next() string {
	return reader.next()
}

func nextInt64() int64 {
	i, err := strconv.ParseInt(reader.next(), 10, 64)
	if err != nil {
		panic(err)
	}
	return i
}

func nextInt() int {
	return int(nextInt64())
}

func nextLine() string {
	return reader.nextLine()
}

func out(a ...interface{}) {
	fmt.Fprintln(writer, a...)
}

func max64(x, y int64) int64 {
	if x > y {
		return x
	}
	return y
}

func max(x, y int) int {
	return int(max64(int64(x), int64(y)))
}

func min64(x, y int64) int64 {
	if x < y {
		return x
	}
	return y
}

func min(x, y int) int {
	return int(min64(int64(x), int64(y)))
}

func abs64(x int64) int64 {
	if x < 0 {
		return -x
	}
	return x
}

func abs(x int) int {
	return int(abs64(int64(x)))
}

func joinInt64s(a []int64, sep string) string {
	b := make([]string, len(a))
	for i, v := range a {
		b[i] = strconv.FormatInt(v, 10)
	}
	return strings.Join(b, sep)
}

func joinInts(a []int, sep string) string {
	b := make([]string, len(a))
	for i, v := range a {
		b[i] = strconv.Itoa(v)
	}
	return strings.Join(b, sep)
}

func divUp64(x, y int64) int64 {
	return (x + y - 1) / y
}

func divUp(x, y int) int {
	return int(divUp64(int64(x), int64(y)))
}

func gcd64(x, y int64) int64 {
	if x < y {
		x, y = y, x
	}
	for y != 0 {
		x, y = y, x%y
	}
	return x
}

func gcd(x, y int) int {
	return int(gcd64(int64(x), int64(y)))
}

func lcm64(x, y int64) int64 {
	return x * y / gcd64(x, y)
}

func lcm(x, y int) int {
	return int(lcm64(int64(x), int64(y)))
}

func main() {
	solve()
	writer.Flush()
}

func solve() {
	s := nextLine()
	c := strings.Index(s, "C")
	if c == -1 {
		out("No")
		return
	}
	f := strings.Index(s[c:], "F")
	if f == -1 {
		out("No")
		return
	}
	out("Yes")
}

Score : 100 points

Problem Statement

This contest is CODEFESTIVAL, which can be shortened to the string CF by deleting some characters.

Mr. Takahashi, full of curiosity, wondered if he could obtain CF from other strings in the same way.

You are given a string s consisting of uppercase English letters.
Determine whether the string CF can be obtained from the string s by deleting some characters.

Constraints

2 ≤ |s| ≤ 100

All characters in s are uppercase English letters (A-Z).

Input

The input is given from Standard Input in the following format:

s

Output

Print Yes if the string CF can be obtained from the string s by deleting some characters.
Otherwise print No.

Sample Input 1

CODEFESTIVAL

Sample Output 1

Yes

CF is obtained by deleting characters other than the first character C and the fifth character F.

Sample Input 2

FESTIVALCODE

Sample Output 2

No

FC can be obtained but CF cannot be obtained because you cannot change the order of the characters.

Sample Input 3

CF

Sample Output 3

Yes

It is also possible not to delete any characters.

Sample Input 4

FCF

Sample Output 4

Yes

CF is obtained by deleting the first character.


// 明らかに最大のやつに引っ張られる
// それ以外のやつは最大のやつの合間にはさめばいいので、max(A)-1<=max(A)以外の合計、ならばいける
// いけない場合はmax(A)-1-max(A)以外の合計かな
package main

import "fmt"

var k, t int

func main() {
	fmt.Scan(&k, &t)
	max_a := -1
	for i := 0; i < t; i++ {
		var j int
		fmt.Scan(&j)
		if j > max_a {
			max_a = j
		}
	}
	sum := k - max_a
	if max_a-1 <= sum {
		fmt.Println(0)
	} else {
		fmt.Println(max_a - 1 - sum)
	}
}

Global OOD problem IDs are disjoint from train, validation, and in-distribution test problem IDs.

Score : 200 points

Problem Statement

There are K pieces of cakes.
Mr. Takahashi would like to eat one cake per day, taking K days to eat them all.

There are T types of cake, and the number of the cakes of type i (1 ≤ i ≤ T) is a_i.

Eating the same type of cake two days in a row would be no fun,
so Mr. Takahashi would like to decide the order for eating cakes that minimizes the number of days on which he has to eat the same type of cake as the day before.

Compute the minimum number of days on which the same type of cake as the previous day will be eaten.

Constraints

1 ≤ K ≤ 10000

1 ≤ T ≤ 100

1 ≤ a_i ≤ 100

a_1 + a_2 + ... + a_T = K

Input

The input is given from Standard Input in the following format:

K T
a_1 a_2 ... a_T

Output

Print the minimum number of days on which the same type of cake as the previous day will be eaten.

Sample Input 1

7 3
3 2 2

Sample Output 1

0

For example, if Mr. Takahashi eats cakes in the order of 2, 1, 2, 3, 1, 3, 1, he can avoid eating the same type of cake as the previous day.

Sample Input 2

6 3
1 4 1

Sample Output 2

1

There are 6 cakes.
For example, if Mr. Takahashi eats cakes in the order of 2, 3, 2, 2, 1, 2, he has to eat the same type of cake (i.e., type 2) as the previous day only on the fourth day.
Since this is the minimum number, the answer is 1.

Sample Input 3

100 1
100

Sample Output 3

99

Since Mr. Takahashi has only one type of cake, he has no choice but to eat the same type of cake as the previous day from the second day and after.

Submitted source-code file size, in bytes.

Execution CPU time reported by official Project CodeNet metadata, in milliseconds.

Peak memory usage reported by official Project CodeNet metadata, in kilobytes.


///
// File:  c.go
// Author: ymiyamoto
//
// Created on Sat May 26 17:04:42 2018
//
package main

import (
	"fmt"
)

const MOD int64 = 1e9 + 7

var N int
var T, A []int64

func max(a, b int64) int64 {
	if a < b {
		return b
	}
	return a
}

func min(a, b int64) int64 {
	if a < b {
		return a
	}
	return b
}

func main() {
	fmt.Scan(&N)
	T = make([]int64, N)
	A = make([]int64, N)

	max_t := int64(0)
	for i := range T {
		fmt.Scan(&T[i])
		max_t = max(max_t, T[i])
	}

	max_a := int64(0)
	for i := range A {
		fmt.Scan(&A[i])
		max_a = max(max_a, A[i])
	}

	if max_a != max_t {
		fmt.Println(0)
		return
	}

	dp := make([]int64, N)
	for i := range T {
		if i != 0 {
			if T[i] != T[i-1] {
				dp[i] = 1
			} else {
				dp[i] = T[i]
			}
		} else {
			dp[i] = 1
		}
	}

	dp2 := make([]int64, N)
	for i := len(A) - 1; i >= 0; i-- {
		if i != len(A)-1 {
			if A[i] != A[i+1] {
				dp2[i] = 1
			} else {
				dp2[i] = A[i]
			}
		} else {
			dp2[i] = 1
		}
	}

	fmt.Println(dp)
	fmt.Println(dp2)

	ans := int64(1)
	for i := range dp {
		ans *= min(dp[i], dp2[i]) % MOD
		ans %= MOD
	}
	fmt.Println(ans)
}

Score : 400 points

Problem Statement

Mountaineers Mr. Takahashi and Mr. Aoki recently trekked across a certain famous mountain range.
The mountain range consists of N mountains, extending from west to east in a straight line as Mt. 1, Mt. 2, ..., Mt. N.
Mr. Takahashi traversed the range from the west and Mr. Aoki from the east.

The height of Mt. i is h_i, but they have forgotten the value of each h_i.
Instead, for each i (1 ≤ i ≤ N), they recorded the maximum height of the mountains climbed up to the time they reached the peak of Mt. i (including Mt. i).
Mr. Takahashi's record is T_i and Mr. Aoki's record is A_i.

We know that the height of each mountain h_i is a positive integer.
Compute the number of the possible sequences of the mountains' heights, modulo 10^9 + 7.

Note that the records may be incorrect and thus there may be no possible sequence of the mountains' heights.
In such a case, output 0.

Constraints

1 ≤ N ≤ 10^5

1 ≤ T_i ≤ 10^9

1 ≤ A_i ≤ 10^9

T_i ≤ T_{i+1} (1 ≤ i ≤ N - 1)

A_i ≥ A_{i+1} (1 ≤ i ≤ N - 1)

Input

The input is given from Standard Input in the following format:

N
T_1 T_2 ... T_N
A_1 A_2 ... A_N

Output

Print the number of possible sequences of the mountains' heights, modulo 10^9 + 7.

Sample Input 1

5
1 3 3 3 3
3 3 2 2 2

Sample Output 1

4

The possible sequences of the mountains' heights are:

1, 3, 2, 2, 2

1, 3, 2, 1, 2

1, 3, 1, 2, 2

1, 3, 1, 1, 2

for a total of four sequences.

Sample Input 2

5
1 1 1 2 2
3 2 1 1 1

Sample Output 2

0

The records are contradictory, since Mr. Takahashi recorded 2 as the highest peak after climbing all the mountains but Mr. Aoki recorded 3.

Sample Input 3

10
1 3776 3776 8848 8848 8848 8848 8848 8848 8848
8848 8848 8848 8848 8848 8848 8848 8848 3776 5

Sample Output 3

884111967

Don't forget to compute the number modulo 10^9 + 7.

Sample Input 4

1
17
17

Sample Output 4

1

Some mountain ranges consist of only one mountain.


package main

import (
	"fmt"
)

func main() {
	var a, b, c, ans int
	fmt.Scan(&a, &b, &c)

	if a == b && b == c {
		ans = 1
	} else if a == b || b == c || c == a {
		ans = 2
	} else {
		ans = 3
	}

	fmt.Println(ans)
}

Score : 100 points

Problem Statement

AtCoDeer the deer recently bought three paint cans.
The color of the one he bought two days ago is a, the color of the one he bought yesterday is b, and the color of the one he bought today is c.
Here, the color of each paint can is represented by an integer between 1 and 100, inclusive.

Since he is forgetful, he might have bought more than one paint can in the same color.
Count the number of different kinds of colors of these paint cans and tell him.

Constraints

1≦a,b,c≦100

Input

The input is given from Standard Input in the following format:

a b c

Output

Print the number of different kinds of colors of the paint cans.

Sample Input 1

3 1 4

Sample Output 1

3

Three different colors: 1, 3, and 4.

Sample Input 2

3 3 33

Sample Output 2

2

Two different colors: 3 and 33.


package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func main() {
	scanInit()

	n := nextInt()
	k := nextInt()
	ans := k
	for i := 1; i < n; i++ {
		ans *= k - 1
	}

	fmt.Println(ans)

}

// ---- readfunc
func scanInit() {
	const cap = 200 * 1024 // Default=64
	var buf = make([]byte, cap)
	sc.Buffer(buf, cap)
	sc.Split(bufio.ScanWords)
	return
}
func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}
func nextStr() string {
	sc.Scan()
	return sc.Text()
}

Score : 200 points

Problem Statement

There are N balls placed in a row.
AtCoDeer the deer is painting each of these in one of the K colors of his paint cans.
For aesthetic reasons, any two adjacent balls must be painted in different colors.

Find the number of the possible ways to paint the balls.

Constraints

1≦N≦1000

2≦K≦1000

The correct answer is at most 2^{31}-1.

Input

The input is given from Standard Input in the following format:

N K

Output

Print the number of the possible ways to paint the balls.

Sample Input 1

2 2

Sample Output 1

2

We will denote the colors by 0 and 1. There are two possible ways: we can either paint the left ball in color 0 and the right ball in color 1, or paint the left in color 1 and the right in color 0.

Sample Input 2

1 10

Sample Output 2

10

Since there is only one ball, we can use any of the ten colors to paint it. Thus, the answer is ten.


package main

import (
  "fmt"
  "math"
)

func ceildiv(x, y int) int {
  return int(math.Ceil(float64(x) / float64(y)))
}

func main() {
  var n int
  var x, y int
  fmt.Scan(&n)
  a, b := 1, 1
  for i := 0; i < n; i++ {
    fmt.Scan(&x, &y)
    mx := ceildiv(a, x)
    my := ceildiv(b, y)
    m := my
    if mx > m {
      m = mx
    }
    a = m * x
    b = m * y
  }
  fmt.Println(a + b)
}

Score : 300 points

Problem Statement

AtCoDeer the deer is seeing a quick report of election results on TV.
Two candidates are standing for the election: Takahashi and Aoki.
The report shows the ratio of the current numbers of votes the two candidates have obtained, but not the actual numbers of votes.
AtCoDeer has checked the report N times, and when he checked it for the i-th (1≦i≦N) time, the ratio was T_i:A_i.
It is known that each candidate had at least one vote when he checked the report for the first time.

Find the minimum possible total number of votes obtained by the two candidates when he checked the report for the N-th time.
It can be assumed that the number of votes obtained by each candidate never decreases.

Constraints

1≦N≦1000

1≦T_i,A_i≦1000 (1≦i≦N)

T_i and A_i (1≦i≦N) are coprime.

It is guaranteed that the correct answer is at most 10^{18}.

Input

The input is given from Standard Input in the following format:

N
T_1 A_1
T_2 A_2
:
T_N A_N

Output

Print the minimum possible total number of votes obtained by Takahashi and Aoki when AtCoDeer checked the report for the N-th time.

Sample Input 1

3
2 3
1 1
3 2

Sample Output 1

10

When the numbers of votes obtained by the two candidates change as 2,3 → 3,3 → 6,4, the total number of votes at the end is 10, which is the minimum possible number.

Sample Input 2

4
1 1
1 1
1 5
1 100

Sample Output 2

101

It is possible that neither candidate obtained a vote between the moment when he checked the report, and the moment when he checked it for the next time.

Sample Input 3

5
3 10
48 17
31 199
231 23
3 2

Sample Output 3

6930


package main

import "fmt"

func main() {
	var x string
	fmt.Scan(&x)

	ans := 0
	sta := 0
	for _, xx := range x {
		if xx == 'S' {
			sta++
		} else {
			if sta > 0 {
				sta--
			} else {
				ans++
			}
		}
	}

	fmt.Println(ans + sta)
}

Score : 300 points

Problem Statement

We have a string X, which has an even number of characters. Half the characters are S, and the other half are T.

Takahashi, who hates the string ST, will perform the following operation 10^{10000} times:

Among the occurrences of ST in X as (contiguous) substrings, remove the leftmost one. If there is no occurrence, do nothing.

Find the eventual length of X.

Constraints

2 ≦ |X| ≦ 200,000

The length of X is even.

Half the characters in X are S, and the other half are T.

Partial Scores

In test cases worth 200 points, |X| ≦ 200.

Input

The input is given from Standard Input in the following format:

X

Output

Print the eventual length of X.

Sample Input 1

TSTTSS

Sample Output 1

4

In the 1-st operation, the 2-nd and 3-rd characters of TSTTSS are removed.
X becomes TTSS, and since it does not contain ST anymore, nothing is done in the remaining 10^{10000}-1 operations.
Thus, the answer is 4.

Sample Input 2

SSTTST

Sample Output 2

0

X will eventually become an empty string: SSTTST ⇒ STST ⇒ ST ⇒ ``.

Sample Input 3

TSSTTTSS

Sample Output 3

4

X will become: TSSTTTSS ⇒ TSTTSS ⇒ TTSS.


package main

import (
    "fmt"
    "os"
    "bufio"
)

func main() {
    var fp *os.File
    fp = os.Stdin
    reader := bufio.NewReaderSize(fp, 4096)
    X := readLine(reader)
    arr := []byte(X)
    length := len(arr)
    var flag int = 0
    var cnt int = 0

    for i := length - 1; i >= 0; i-- {
        if flag == 0 {
            if string(arr[i]) == "T" {
                flag = 1
            }
        } else {
            if string(arr[i]) == "S" {
                cnt++
            }
        }
    }

    fmt.Println(length - cnt*2)
}

func readLine(reader *bufio.Reader) string {
    buf := make([]byte, 0, 1024)

    for {
        l, p, _ := reader.ReadLine()

        buf = append(buf, l...)

        if !p {
            break
        }
    }

    return string(buf)
}


package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}

func getNextUint64(scanner *bufio.Scanner) uint64 {
	i, _ := strconv.ParseUint(getNextString(scanner), 10, 64)
	return i
}

func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}
	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	seg := Segment{}
	seg.init(n)
	aa := make([]int, n)
	for i := 0; i < n; i++ {
		aa[getNextInt(scanner)-1] = i
	}
	var ans int64
	for i := 0; i < n; i++ {
		seg.add(aa[i], 1)
		l := seg.nextLeft(aa[i])
		r := seg.nextRight(aa[i])
		ans += int64(aa[i]-l) * int64(r-aa[i]) * int64(i+1)

	}

	fmt.Fprintln(writer, ans)
	writer.Flush()
}

// Segment ...
type Segment struct {
	n, h, i int
	unit    []int
	bucket  [][]int
}

func (seg *Segment) init(n int) {
	seg.n = n
	seg.unit = make([]int, 1)
	seg.unit[0] = 1
	seg.bucket = make([][]int, 1)
	seg.bucket[0] = make([]int, n)

	chunk := 32
	i := 0
	for n > chunk+1 {
		n = (n-1)/chunk + 1
		seg.bucket = append(seg.bucket, make([]int, n))
		seg.unit = append(seg.unit, seg.unit[i]*chunk)
		i++
	}
	seg.h = len(seg.unit)
}

func (seg *Segment) add(index, value int) {
	for i := 0; i < seg.h; i++ {
		seg.bucket[i][index/seg.unit[i]] += value
	}
}

func (seg *Segment) nextLeft(index int) int {
	raw := seg.bucket[0]
	for index = index - 1; index >= 0; index-- {
		if raw[index] > 0 {
			return index
		}
		for seg.i = 0; seg.i < seg.h; seg.i++ {
			if (index+1)%seg.unit[seg.i] != 0 {
				break
			}
			if seg.bucket[seg.i][index/seg.unit[seg.i]] != 0 {
				break
			}
		}
		seg.i--
		index -= seg.unit[seg.i] - 1
	}

	return -1
}

func (seg *Segment) nextRight(index int) int {
	raw := seg.bucket[0]
	for index = index + 1; index < seg.n; index++ {
		if raw[index] > 0 {
			return index
		}
		for seg.i = 0; seg.i < seg.h; seg.i++ {
			if index%seg.unit[seg.i] != 0 {
				break
			}
			if seg.bucket[seg.i][index/seg.unit[seg.i]] != 0 {
				break
			}
		}
		seg.i--

		index += seg.unit[seg.i] - 1
	}

	return seg.n
}

func (seg *Segment) get(index int) int {
	for i := 0; i < seg.n; i++ {
		for seg.i = 0; seg.i < seg.h; seg.i++ {
			if index%seg.unit[seg.i] != 0 {
				break
			}
			if seg.bucket[seg.i][index/seg.unit[seg.i]] >= index {
				break
			}
		}
		seg.i--

		index -= seg.bucket[seg.i][index/seg.unit[seg.i]]
		i += seg.unit[seg.i] - 1

		if index == 0 {
			return i
		}
	}

	return -1
}

Score : 400 points

Problem Statement

One day, Snuke was given a permutation of length N, a_1, a_2, ..., a_N, from his friend.

Find the following:

Constraints

1 ≦ N ≦ 200,000

(a_1, a_2, ..., a_N) is a permutation of (1, 2, ..., N).

Input

The input is given from Standard Input in the following format:

N
a_1 a_2 ... a_N

Output

Print the answer.

Note that the answer may not fit into a 32-bit integer.

Sample Input 1

3
2 1 3

Sample Output 1

9

Sample Input 2

4
1 3 2 4

Sample Output 2

19

Sample Input 3

8
5 4 8 1 2 6 7 3

Sample Output 3

85


package main

import (
	"bufio"
	"os"
	"strconv"
	"fmt"
)

type Scanner struct {
	r   *bufio.Reader
	buf []byte
	p   int
}

func NewScanner() *Scanner {
	rdr := bufio.NewReaderSize(os.Stdin, 1000)
	return &Scanner{r:rdr}
}
func (s *Scanner) Next() string {
	s.pre()
	start := s.p
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			break
		}
	}
	result := string(s.buf[start:s.p])
	s.p++
	return result
}
func (s *Scanner) NextLine() string {
	s.pre()
	start := s.p
	s.p = len(s.buf)
	return string(s.buf[start:])
}
func (s *Scanner) NextInt() int {
	v, _ := strconv.Atoi(s.Next())
	return v
}

func (s *Scanner) NextIntArray() []int {
	s.pre()
	start := s.p
	result := []int{}
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			v, _ := strconv.Atoi(string(s.buf[start:s.p]))
			result = append(result, v)
			start = s.p + 1
		}
	}
	v, _ := strconv.Atoi(string(s.buf[start:s.p]))
	result = append(result, v)

	return result
}

func (s *Scanner) NextMap() map[int]bool {
	s.pre()
	start := s.p
	mp := map[int]bool{}
	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			v, _ := strconv.Atoi(string(s.buf[start:s.p]))
			mp[v] = true
			start = s.p + 1
		}
	}
	v, _ := strconv.Atoi(string(s.buf[start:s.p]))
	mp[v] = true

	return mp
}

func (s *Scanner) pre() {
	if s.p >= len(s.buf) {
		s.readLine()
		s.p = 0
	}
}
func (s *Scanner) readLine() {
	s.buf = make([]byte, 0)
	for {
		l, p, e := s.r.ReadLine()
		if e != nil {
			panic(e)
		}
		s.buf = append(s.buf, l...)
		if !p {
			break
		}
	}
}

func main() {
	sc := NewScanner()
	S := sc.NextLine()
	N := sc.NextInt()

	s := make([]int, len(S))
	for i := 0; i < len(S); i++ {
		s[i] = int(S[i] - 'a')
	}
	for i := 0; i < len(s) - 1; i++ {
		if s[i] == 0 {
			continue
		}
		if 26 - s[i] <= N {
			N -= 26 - s[i]
			s[i] = 0
		}
	}
	p := len(s) - 1

	N %= 26
	s[p] += N
	s[p] %= 26
	for i := 0; i < len(s); i++ {
		fmt.Print(string(s[i] + 'a'))
	}
	fmt.Println()

}

Score : 100 points

Problem Statement

This contest is CODE FESTIVAL.
However, Mr. Takahashi always writes it CODEFESTIVAL, omitting the single space between CODE and FESTIVAL.

So he has decided to make a program that puts the single space he omitted.

You are given a string s with 12 letters.
Output the string putting a single space between the first 4 letters and last 8 letters in the string s.

Constraints

s contains exactly 12 letters.

All letters in s are uppercase English letters.

Input

The input is given from Standard Input in the following format:

s

Output

Print the string putting a single space between the first 4 letters and last 8 letters in the string s.
Put a line break at the end.

Sample Input 1

CODEFESTIVAL

Sample Output 1

CODE FESTIVAL

Putting a single space between the first 4 letters and last 8 letters in CODEFESTIVAL makes it CODE FESTIVAL.

Sample Input 2

POSTGRADUATE

Sample Output 2

POST GRADUATE

Sample Input 3

ABCDEFGHIJKL

Sample Output 3

ABCD EFGHIJKL


package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

const (
	initialBufSize = 1e4
	maxBufSize     = 1e6 + 7
)

var buf []byte = make([]byte, maxBufSize)
var sc = bufio.NewScanner(os.Stdin)

func init() {
	sc.Split(bufio.ScanWords)
	sc.Buffer(buf, maxBufSize)
}

func main() {
	N := nextInt()
	An := make([]int, N)
	ans := 0
	for i := range An {
		An[i] = nextInt()
	}
	for i := 0; i < N; i++ {
		if An[An[i]-1]-1 == i {
			ans++
		}
	}
	fmt.Println(ans / 2)
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

Score : 200 points

Problem Statement

There are N rabbits, numbered 1 through N.

The i-th (1≤i≤N) rabbit likes rabbit a_i.
Note that no rabbit can like itself, that is, a_i≠i.

For a pair of rabbits i and j (i＜j), we call the pair (i，j) a friendly pair if the following condition is met.

Rabbit i likes rabbit j and rabbit j likes rabbit i.

Calculate the number of the friendly pairs.

Constraints

2≤N≤10^5

1≤a_i≤N

a_i≠i

Input

The input is given from Standard Input in the following format:

N
a_1 a_2 ... a_N

Output

Print the number of the friendly pairs.

Sample Input 1

4
2 1 4 3

Sample Output 1

2

There are two friendly pairs: (1，2) and (3，4).

Sample Input 2

3
2 3 1

Sample Output 2

0

There are no friendly pairs.

Sample Input 3

5
5 5 5 5 1

Sample Output 3

1

There is one friendly pair: (1，5).


// ProblemURL : https://atcoder.jp/contests/code-festival-2016-quala/tasks/codefestival_2016_qualA_c
// ---------------------------------------------
package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"sort"
	"strconv"
	"strings"
)

func abs(x int) int {
	if x < 0 {
		return -x
	}
	return x
}
func diff(a, b int) int {
	if a > b {
		return a - b
	}
	return b - a
}
func larger(a, b int) int {
	if a > b {
		return a
	}
	return b
}
func smaller(a, b int) int {
	if a < b {
		return a
	}
	return b
}
func largest(a, b, c int) (lgst int) {
	if a > b {
		lgst = a
	} else {
		lgst = b
	}
	if c > lgst {
		lgst = c
	}
	return
}
func smallest(a, b, c int) (slst int) {
	if a < b {
		slst = a
	} else {
		slst = b
	}
	if c < slst {
		slst = c
	}
	return
}
func intsMax(a []int) (idx, val int) {
	if len(a) == 0 {
		panic("func max: argument slice length must not be zero")
	}
	val = a[0]
	for i, aa := range a {
		if aa > val {
			idx, val = i, aa
		}
	}
	return
}
func intsMin(a []int) (idx, val int) {
	if len(a) == 0 {
		panic("func min: argument slice length must not be zero")
	}
	val = a[0]
	for i, aa := range a {
		if aa < val {
			idx, val = i, aa
		}
	}
	return
}
func intsSum(a []int) int {
	res := 0
	for _, v := range a {
		res += v
	}
	return res
}
func isEven(n int) bool            { return n&1 == 0 }
func isOdd(n int) bool             { return n&1 == 1 }
func swap(a int, b int) (int, int) { return b, a }
func calcMod(n int) int            { return n % mod }
func ceil(x float64) int           { return int(math.Ceil(x)) }
func pow(x, y int) int {
	if y < 0 {
		panic("Exponent must be a natural number")
	}
	z := 1
	for i := y; i != 0; i >>= 1 {
		if i&1 == 1 {
			z *= x
		}
		x *= x
	}
	return z
}
func powMod(x, y int) int {
	if y < 0 {
		panic("Exponent must be a natural number")
	}
	z := 1
	for i := y; i != 0; i >>= 1 {
		if i&1 == 1 {
			z = (z * x) % mod
		}
		x = (x * x) % mod
	}
	return z
}
func sigmaK(n int) int          { return n * (n + 1) / 2 }
func sigmaKK(n int) int         { return (n * (n + 1) / 2) * (2*n + 1) / 3 }
func intsJoin(a, b []int) []int { return append(a, b...) }
func intsClear(a []int) []int   { return a[:0] }
func intsCopy(a []int) []int    { return append([]int(nil), a...) }
func intsSorted(a []int) []int {
	s := intsCopy(a)
	sort.Ints(s)
	return s
}
func intsReverse(a []int) {
	for i, j := 0, len(a)-1; i < j; i, j = i+1, j-1 {
		a[i], a[j] = a[j], a[i]
	}
	return
}
func intsFill(a []int, val int) {
	for i := 0; i < len(a); i++ {
		a[i] = val
	}
	return
}
func intsPeekBack(a []int) int {
	if len(a) == 0 {
		panic("func peekBack: zero length slice")
	}
	return a[len(a)-1]
}
func intsPeekFront(a []int) int {
	if len(a) == 0 {
		panic("func peekFront: zero length slice")
	}
	return a[0]
}
func intsPopBack(a []int) (int, []int) {
	if len(a) == 0 {
		panic("func popBack: zero length slice")
	}
	return a[len(a)-1], a[:len(a)-1]
}
func intsPopFront(a []int) (int, []int) {
	if len(a) == 0 {
		panic("func popFront: zero length slice")
	}
	return a[0], a[1:]
}
func intsPushBack(a []int, x int) []int  { return append(a, x) }
func intsPushFront(a []int, x int) []int { return append([]int{x}, a...) }
func chmax(a *int, b int) {
	if *a < b {
		*a = b
	}
}
func chmin(a *int, b int) {
	if *a > b {
		*a = b
	}
}
func strUpperCase(s string) string { return strings.ToUpper(s) }
func strLowerCase(s string) string { return strings.ToLower(s) }

var (
	sc = bufio.NewScanner(os.Stdin)
	bw = bufio.NewWriterSize(os.Stdout, maxBufSize)
)

func init() {
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1e7), 1e7)
}
func ru() (n int) {
	sc.Scan()
	if err := sc.Err(); err != nil {
		panic(err)
	}
	for _, v := range sc.Bytes() {
		n = n*10 + int(v-48)
	}
	return
}
func ri() (n int) {
	sc.Scan()
	if err := sc.Err(); err != nil {
		panic(err)
	}
	b := sc.Bytes()
	neg := false
	if b[0] == 45 {
		neg = true
		b = b[1:]
	}
	for _, v := range b {
		n = n*10 + int(v-48)
	}
	if neg {
		n = -n
	}
	return
}
func ri64() (n int64) {
	sc.Scan()
	if err := sc.Err(); err != nil {
		panic(err)
	}
	b := sc.Bytes()
	neg := false
	if b[0] == 45 {
		neg = true
		b = b[1:]
	}
	for _, v := range b {
		n = n*10 + int64(v-48)
	}
	if neg {
		n = -n
	}
	return
}
func rf64() float64 {
	sc.Scan()
	if err := sc.Err(); err != nil {
		panic(err)
	}
	f, err := strconv.ParseFloat(sc.Text(), 64)
	if err != nil {
		panic(err)
	}
	return f
}
func rs() string {
	sc.Scan()
	if err := sc.Err(); err != nil {
		panic(err)
	}
	return sc.Text()
}
func rb() []byte {
	sc.Scan()
	if err := sc.Err(); err != nil {
		panic(err)
	}
	return sc.Bytes()
}
func rr() []rune {
	sc.Scan()
	if err := sc.Err(); err != nil {
		panic(err)
	}
	return []rune(sc.Text())
}
func ris(n int) []int {
	s := make([]int, n)
	for i := range s {
		s[i] = ri()
	}
	return s
}
func risZeroBased(n int) []int {
	s := make([]int, n)
	for i := range s {
		s[i] = ri() - 1
	}
	return s
}
func ri64s(n int) []int64 {
	s := make([]int64, n)
	for i := range s {
		s[i] = ri64()
	}
	return s
}
func rss(n int) []string {
	s := make([]string, n)
	for i := range s {
		s[i] = rs()
	}
	return s
}
func pf(format string, a ...interface{}) {
	if _, err := fmt.Fprintf(bw, format, a...); err != nil {
		panic(err)
	}
}
func pln(a ...interface{}) {
	if _, err := fmt.Fprintln(bw, a...); err != nil {
		panic(err)
	}
}
func pall(a []int) {
	for _, v := range a {
		fmt.Fprintln(bw, v)
	}
}
func pallol(a []int) {
	s := fmt.Sprint(a)
	if _, err := fmt.Fprintln(bw, s[1:len(s)-1]); err != nil {
		panic(err)
	}
}
func dbg(a ...interface{}) {
	if _, err := fmt.Fprintln(os.Stderr, a...); err != nil {
		panic(err)
	}
}
func YESorNO(b bool) string {
	if b {
		return "YES"
	} else {
		return "NO"
	}
}
func YesOrNo(b bool) string {
	if b {
		return "Yes"
	} else {
		return "No"
	}
}
func main() {
	solve()
	bw.Flush()
}

const (
	maxBufSize = 1e6

	// maxInt64  = 9223372036854775807  // 9e18
	// maxInt32  = 2147483647           // 2e9
	// maxUint64 = 18446744073709551615 // 1e19
	inf = 1 << 60
	mod = 1e9 + 7

	alphabetUpper = "abcdefghijklmnopqrstuvwxyz"
	alphabetLower = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
)

type pair struct{ a, b int }
type point struct{ x, y int }

func solve() {
	s := rs()
	k := ri()
	n := len(s)

	costs := make([]int, n)
	for i := range s {
		costs[i] = (26 - int(s[i]-'a')) % 26
	}

	ans := make([]byte, 0, n)
	for i := 0; i < n-1; i++ {
		if costs[i] <= k {
			ans = append(ans, 'a')
			k -= costs[i]
		} else {
			ans = append(ans, s[i])
		}
	}
	ans = append(ans, byte((int(s[n-1]-'a')+k)%26+'a'))
	pln(string(ans))
}

Score : 400 points

Problem Statement

Mr. Takahashi has a string s consisting of lowercase English letters.
He repeats the following operation on s exactly K times.

Choose an arbitrary letter on s and change that letter to the next alphabet. Note that the next letter of z is a.

For example, if you perform an operation for the second letter on aaz, aaz becomes abz.
If you then perform an operation for the third letter on abz, abz becomes aba.

Mr. Takahashi wants to have the lexicographically smallest string after performing exactly K operations on s.
Find the such string.

Constraints

1≤|s|≤10^5

All letters in s are lowercase English letters.

1≤K≤10^9

Input

The input is given from Standard Input in the following format:

s
K

Output

Print the lexicographically smallest string after performing exactly K operations on s.

Sample Input 1

xyz
4

Sample Output 1

aya

For example, you can perform the following operations: xyz, yyz, zyz, ayz, aya.

Sample Input 2

a
25

Sample Output 2

z

You have to perform exactly K operations.

Sample Input 3

codefestival
100

Sample Output 3

aaaafeaaivap


package main

import(
	"fmt"
  	"bufio"
  	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func nextLine() int{
  sc.Scan()
  i, _:= strconv.Atoi(sc.Text())
  return i
}

func main(){
  a,b,h := nextLine(),nextLine(),nextLine()
  var total = 0
  if a==b && b == h && a == h{
  	total = b*h
  }else{
    total = (a + b)*h/2
  }
  fmt.Println(total)
}

Score : 100 points

Problem Statement

You are given a trapezoid. The lengths of its upper base, lower base, and height are a, b, and h, respectively.

An example of a trapezoid

Find the area of this trapezoid.

Constraints

1≦a≦100

1≦b≦100

1≦h≦100

All input values are integers.

h is even.

Input

The input is given from Standard Input in the following format:

a
b
h

Output

Print the area of the given trapezoid. It is guaranteed that the area is an integer.

Sample Input 1

3
4
2

Sample Output 1

7

When the lengths of the upper base, lower base, and height are 3, 4, and 2, respectively, the area of the trapezoid is (3+4)×2/2 = 7.

Sample Input 2

4
4
4

Sample Output 2

16

In this case, a parallelogram is given, which is also a trapezoid.


package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
	"sort"
	"strconv"
)

const (
	initialBufSize = 1e4
	maxBufSize     = 1e6 + 7
)

var buf []byte = make([]byte, maxBufSize)
var sc = bufio.NewScanner(os.Stdin)

func init() {
	sc.Split(bufio.ScanWords)
	sc.Buffer(buf, maxBufSize)
}

func main() {
	Sa, Sb, Sc := nextLine(), nextLine(), nextLine()
	cur := Sa[0]
	Sa = Sa[1:]
	for {
		switch cur {
		case 'a':
			if len(Sa) == 1 {
				fmt.Println("A")
				return
			} else {
				Sa = Sa[1:]
			}
			cur = Sa[0]
		case 'b':
			if len(Sb) == 1 {
				fmt.Println("B")
				return
			} else {
				Sb = Sb[1:]
			}
			cur = Sb[0]
		case 'c':
			if len(Sc) == 1 {
				fmt.Println("C")
				return
			} else {
				Sc = Sc[1:]
			}
			cur = Sc[0]
		}
	}
}

func nextLine() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func abs(a int) int {
	if a > 0 {
		return a
	} else {
		return -a
	}
}

func pow(p, q int) int {
	res := p
	if q == 0 {
		return 1
	}
	for i := 0; i < q-1; i++ {
		res *= p
	}
	return res
}

func MinOf(vars ...int) int {
	min := vars[0]
	for _, i := range vars {
		if min > i {
			min = i
		}
	}
	return min
}

func MaxOf(vars ...int) int {
	max := vars[0]
	for _, i := range vars {
		if max < i {
			max = i
		}
	}
	return max
}

func gcdof2numbers(a int, b int) int {
	if b == 0 {
		return a
	}
	return gcdof2numbers(b, a%b)
}

func lcmof2numbers(a int, b int) int {
	return a / gcdof2numbers(a, b) * b
}

// マイナスの場合は考慮していない
func fuctorial(a int) int {
	if a == 1 || a == 0 {
		return 1
	} else {
		return fuctorial(a-1) * a
	}
}

func NextPermutation(x sort.Interface) bool {
	n := x.Len() - 1
	if n < 1 {
		return false
	}
	j := n - 1
	for ; !x.Less(j, j+1); j-- {
		if j == 0 {
			return false
		}
	}
	l := n
	for !x.Less(j, l) {
		l--
	}
	x.Swap(j, l)
	for k, l := j+1, n; k < l; {
		x.Swap(k, l)
		k++
		l--
	}
	return true
}

// 素因数分解したmapを返す
func primeFuctorize(n int) map[int]int {
	pf := map[int]int{}
	for i := 2; i*i <= n; i++ {
		for n%i == 0 {
			pf[i]++
			n /= i
		}
	}
	if n != 1 {
		pf[n]++
	}
	return pf
}

// ここから拝借
// https://shoman.hatenablog.com/entry/2020/02/25/185456
// Stackは[]intのエイリアス
type Stack []int

// Push adds an element
func (s *Stack) Push(v int) {
	*s = append(*s, v)
}

// Pop removes the top element and return it
func (s *Stack) Pop() (int, error) {
	if s.Empty() {
		return 0, fmt.Errorf("stack is empty")
	}

	v := (*s)[len(*s)-1]
	*s = (*s)[:len(*s)-1]
	return v, nil
}

// Peek returns the top value
func (s *Stack) Peek() (int, error) {
	if s.Empty() {
		return 0, fmt.Errorf("stack is empty")
	}

	return (*s)[len(*s)-1], nil
}

// Size returns the length of stack
func (s *Stack) Size() int {
	return len(*s)
}

// Empty returns true when stack is empty
func (s *Stack) Empty() bool {
	return s.Size() == 0
}

// NewStack generates stack
func NewStack() *Stack {
	s := new(Stack)
	return s
}

// golangの公式サンプルより
// https://xn--go-hh0g6u.com/pkg/container/heap/#example__intHeap
// IntHeap は，整数の最小ヒープです。
type IntHeap []int

func (h IntHeap) Len() int           { return len(h) }
func (h IntHeap) Less(i, j int) bool { return h[i] < h[j] }
func (h IntHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *IntHeap) Push(x interface{}) {
	// Push と Pop はポインタレシーバを使っています。
	// なぜなら，スライスの中身だけでなく，スライスの長さも変更するからです。
	*h = append(*h, x.(int))
}

func (h *IntHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

// この例では IntHeap にいくつかの整数を挿入しています。そして，最小値をチェックしてから，
// 優先度順に取り除いています。
func Example_intHeap() {
	h := &IntHeap{2, 1, 5}
	heap.Init(h)
	heap.Push(h, 3)
	fmt.Printf("minimum: %d\n", (*h)[0])
	for h.Len() > 0 {
		fmt.Printf("%d ", heap.Pop(h))
	}
	// Output:
	// minimum: 1
	// 1 2 3 5
}

// golangの公式サンプルより
// https://xn--go-hh0g6u.com/pkg/container/heap/#example__priorityQueue

// Item は，優先キューで管理する項目です。
type Item struct {
	value    string // 値。任意です。
	priority int    // キューにおける優先度
	// index は heap.Interface メソッドで更新されます。
	index int // ヒープにおけるインデックス
}

// PriorityQueue は heap.Interface を実装し，Item のリストを保持します。
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	// Pop が最小ではなく最大の優先度を持つ項目を返して欲しいので，ここでは > を使っています。
	return pq[i].priority > pq[j].priority
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}

func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	old[n-1] = nil  // メモリリークを避ける
	item.index = -1 // 安全のため
	*pq = old[0 : n-1]
	return item
}

// update はキューの Item の優先度と値を更新します。
func (pq *PriorityQueue) update(item *Item, value string, priority int) {
	item.value = value
	item.priority = priority
	heap.Fix(pq, item.index)
}

Score : 200 points

Problem Statement

Alice, Bob and Charlie are playing Card Game for Three, as below:

At first, each of the three players has a deck consisting of some number of cards. Each card has a letter a, b or c written on it. The orders of the cards in the decks cannot be rearranged.

The players take turns. Alice goes first.

If the current player's deck contains at least one card, discard the top card in the deck. Then, the player whose name begins with the letter on the discarded card, takes the next turn. (For example, if the card says a, Alice takes the next turn.)

If the current player's deck is empty, the game ends and the current player wins the game.

You are given the initial decks of the players.
More specifically, you are given three strings S_A, S_B and S_C. The i-th (1≦i≦|S_A|) letter in S_A is the letter on the i-th card in Alice's initial deck. S_B and S_C describes Bob's and Charlie's initial decks in the same way.

Determine the winner of the game.

Constraints

1≦|S_A|≦100

1≦|S_B|≦100

1≦|S_C|≦100

Each letter in S_A, S_B, S_C is a, b or c.

Input

The input is given from Standard Input in the following format:

S_A
S_B
S_C

Output

If Alice will win, print A. If Bob will win, print B. If Charlie will win, print C.

Sample Input 1

aca
accc
ca

Sample Output 1

A

The game will progress as below:

Alice discards the top card in her deck, a. Alice takes the next turn.

Alice discards the top card in her deck, c. Charlie takes the next turn.

Charlie discards the top card in his deck, c. Charlie takes the next turn.

Charlie discards the top card in his deck, a. Alice takes the next turn.

Alice discards the top card in her deck, a. Alice takes the next turn.

Alice's deck is empty. The game ends and Alice wins the game.

Sample Input 2

abcb
aacb
bccc

Sample Output 2

C


/*
URL:
https://atcoder.jp/contests/abc045/tasks/arc061_b
*/

package main

import (
	"bufio"
	"errors"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

/********** FAU standard libraries **********/

//fmt.Sprintf("%b\n", 255) 	// binary expression

/********** I/O usage **********/

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()
//a := ReadFloat64()
//A := ReadFloat64Slice(n)

//str := ZeroPaddingRuneSlice(num, 32)
//str := PrintIntsLine(X...)

/*******************************************************************/

const (
	// General purpose
	MOD          = 1000000000 + 7
	ALPHABET_NUM = 26
	INF_INT64    = math.MaxInt64
	INF_BIT60    = 1 << 60
	INF_INT32    = math.MaxInt32
	INF_BIT30    = 1 << 30
	NIL          = -1

	// for dijkstra, prim, and so on
	WHITE = 0
	GRAY  = 1
	BLACK = 2
)

func init() {
	// bufio.ScanWords <---> bufio.ScanLines
	ReadString = newReadString(os.Stdin, bufio.ScanWords)
	stdout = bufio.NewWriter(os.Stdout)
}

var (
	h, w, n int
	A, B    []int

	memo    map[Coord]int
	answers [15]int
)

type Coord struct {
	x, y int
}

func main() {
	h, w, n = ReadInt3()
	for i := 0; i < n; i++ {
		a, b := ReadInt2()
		A = append(A, a)
		B = append(B, b)
	}

	memo = make(map[Coord]int)
	for i := 0; i < n; i++ {
		a, b := A[i], B[i]

		for dy := -1; dy <= 1; dy++ {
			for dx := -1; dx <= 1; dx++ {
				nx, ny := b+dx, a+dy
				nc := Coord{y: ny, x: nx}
				memo[nc]++
			}
		}
	}

	for k, v := range memo {
		cx, cy := k.x, k.y
		if 2 <= cx && cx <= w-1 && 2 <= cy && cy <= h-1 {
			answers[v]++
		}
	}

	sum := 0
	for i := 1; i < 10; i++ {
		sum += answers[i]
	}
	answers[0] = (h-2)*(w-2) - sum

	for i := 0; i < 10; i++ {
		fmt.Println(answers[i])
	}
}

/*******************************************************************/

/*********** I/O ***********/

var (
	// ReadString returns a WORD string.
	ReadString func() string
	stdout     *bufio.Writer
)

func newReadString(ior io.Reader, sf bufio.SplitFunc) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+9)) // for Codeforces
	r.Split(sf)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// ReadInt returns an integer.
func ReadInt() int {
	return int(readInt64())
}
func ReadInt2() (int, int) {
	return int(readInt64()), int(readInt64())
}
func ReadInt3() (int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64())
}
func ReadInt4() (int, int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64()), int(readInt64())
}

// ReadInt64 returns as integer as int64.
func ReadInt64() int64 {
	return readInt64()
}
func ReadInt64_2() (int64, int64) {
	return readInt64(), readInt64()
}
func ReadInt64_3() (int64, int64, int64) {
	return readInt64(), readInt64(), readInt64()
}
func ReadInt64_4() (int64, int64, int64, int64) {
	return readInt64(), readInt64(), readInt64(), readInt64()
}

func readInt64() int64 {
	i, err := strconv.ParseInt(ReadString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// ReadIntSlice returns an integer slice that has n integers.
func ReadIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt()
	}
	return b
}

// ReadInt64Slice returns as int64 slice that has n integers.
func ReadInt64Slice(n int) []int64 {
	b := make([]int64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt64()
	}
	return b
}

// ReadFloat64 returns an float64.
func ReadFloat64() float64 {
	return float64(readFloat64())
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(ReadString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func ReadFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func ReadRuneSlice() []rune {
	return []rune(ReadString())
}

/*********** Debugging ***********/

// ZeroPaddingRuneSlice returns binary expressions of integer n with zero padding.
// For debugging use.
func ZeroPaddingRuneSlice(n, digitsNum int) []rune {
	sn := fmt.Sprintf("%b", n)

	residualLength := digitsNum - len(sn)
	if residualLength <= 0 {
		return []rune(sn)
	}

	zeros := make([]rune, residualLength)
	for i := 0; i < len(zeros); i++ {
		zeros[i] = '0'
	}

	res := []rune{}
	res = append(res, zeros...)
	res = append(res, []rune(sn)...)

	return res
}

// Strtoi is a wrapper of strconv.Atoi().
// If strconv.Atoi() returns an error, Strtoi calls panic.
func Strtoi(s string) int {
	if i, err := strconv.Atoi(s); err != nil {
		panic(errors.New("[argument error]: Strtoi only accepts integer string"))
	} else {
		return i
	}
}

// PrintIntsLine returns integers string delimited by a space.
func PrintIntsLine(A ...int) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.Itoa(A[i])
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

// PrintIntsLine returns integers string delimited by a space.
func PrintInts64Line(A ...int64) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.FormatInt(A[i], 10) // 64bit int version
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

// PrintfDebug is wrapper of fmt.Fprintf(os.Stderr, format, a...)
func PrintfDebug(format string, a ...interface{}) {
	fmt.Fprintf(os.Stderr, format, a...)
}

// PrintfBufStdout is function for output strings to buffered os.Stdout.
// You may have to call stdout.Flush() finally.
func PrintfBufStdout(format string, a ...interface{}) {
	fmt.Fprintf(stdout, format, a...)
}

Score : 400 points

Problem Statement

We have a grid with H rows and W columns. At first, all cells were painted white.

Snuke painted N of these cells. The i-th ( 1 \leq i \leq N ) cell he painted is the cell at the a_i-th row and b_i-th column.

Compute the following:

For each integer j ( 0 \leq j \leq 9 ), how many subrectangles of size 3×3 of the grid contains exactly j black cells, after Snuke painted N cells?

Constraints

3 \leq H \leq 10^9

3 \leq W \leq 10^9

0 \leq N \leq min(10^5,H×W)

1 \leq a_i \leq H (1 \leq i \leq N)

1 \leq b_i \leq W (1 \leq i \leq N)

(a_i, b_i) \neq (a_j, b_j) (i \neq j)

Input

The input is given from Standard Input in the following format:

H W N
a_1 b_1
:
a_N b_N

Output

Print 10 lines.
The (j+1)-th ( 0 \leq j \leq 9 ) line should contain the number of the subrectangles of size 3×3 of the grid that contains exactly j black cells.

Sample Input 1

4 5 8
1 1
1 4
1 5
2 3
3 1
3 2
3 4
4 4

Sample Output 1

0
0
0
2
4
0
0
0
0
0

There are six subrectangles of size 3×3. Two of them contain three black cells each, and the remaining four contain four black cells each.

Sample Input 2

10 10 20
1 1
1 4
1 9
2 5
3 10
4 2
4 7
5 9
6 4
6 6
6 7
7 1
7 3
7 7
8 1
8 5
8 10
9 2
10 4
10 9

Sample Output 2

4
26
22
10
2
0
0
0
0
0

Sample Input 3

1000000000 1000000000 0

Sample Output 3

999999996000000004
0
0
0
0
0
0
0
0
0


package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"io/ioutil"
	"os"
)

type contest struct {
	in  io.Reader
	out io.Writer
}

func (con *contest) scan(a ...interface{}) (int, error) {
	return fmt.Fscan(con.in, a...)
}
func (con *contest) scanln(a ...interface{}) (int, error) {
	return fmt.Fscanln(con.in, a...)
}
func (con *contest) scanf(f string, a ...interface{}) (int, error) {
	return fmt.Fscanf(con.in, f, a...)
}
func (con *contest) print(a ...interface{}) (int, error) {
	return fmt.Fprint(con.out, a...)
}
func (con *contest) println(a ...interface{}) (int, error) {
	return fmt.Fprintln(con.out, a...)
}
func (con *contest) printf(f string, a ...interface{}) (int, error) {
	return fmt.Fprintf(con.out, f, a...)
}
func main() {
	//in := bufio.NewReader(os.Stdin)
	b, _ := ioutil.ReadAll(os.Stdin)
	in := bytes.NewBuffer(b)
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()
	con := &contest{in: in, out: out}
	con.main()
}

type p struct{ r, c int }

func (con *contest) main() error {
	var H, W, N int
	con.scan(&H, &W, &N)
	M := map[p]int{}
	for i := 0; i < N; i++ {
		var a, b int
		con.scan(&a, &b)
		for r := a - 3; r < a; r++ {
			if r < 0 || r > H-3 {
				continue
			}
			for c := b - 3; c < b; c++ {
				if c < 0 || c > W-3 {
					continue
				}
				M[p{r, c}]++
			}
		}
	}
	A := make([]int, 10)
	for _, v := range M {
		A[v]++
	}
	A[0] = (H-2)*(W-2) - len(M)
	for _, a := range A {
		con.println(a)
	}
	return nil
}


package main

import (
	"fmt"
	"strconv"
	"strings"
)

var sum int

func main() {
	var s string
	fmt.Scan(&s)
	a := toSlice(s)
	p := make([]int, len(a)-1)

	solve(a, 0, 1, &p)
	solve(a, 0, -1, &p)
	fmt.Println(sum)
}

func toSlice(s string) []int {
	var a []int
	for i := 0; i < len(s); i++ {
		a = append(a, toInt(string(s[i])))
	}
	return a
}

func solve(a []int, i int, b int, p *[]int) {
	if i == len(a)-1 {
		return
	}
	(*p)[i] = b
	if i == (len(a) - 2) {
		sum += getSum(genNum(a, p))
	}
	solve(a, i+1, 1, p)
	solve(a, i+1, -1, p)
}

func genNum(a []int, p *[]int) string {
	var s string
	for j := 0; j < len(a)-1; j++ {
		s += fmt.Sprintf("%d", a[j])
		if (*p)[j] == 1 {
			s += "+"
		}
	}
	s += fmt.Sprintf("%d", a[len(a)-1])
	return s
}

func getSum(s string) int {
	sum := 0
	for _, v := range strings.Split(s, "+") {
		sum += toInt(v)
	}
	return sum
}

func toInt(s string) int {
	i, err := strconv.Atoi(s)
	if err != nil {
		panic(err)
	}
	return i
}

Score : 300 points

Problem Statement

You are given a string S consisting of digits between 1 and 9, inclusive.
You can insert the letter + into some of the positions (possibly none) between two letters in this string.
Here, + must not occur consecutively after insertion.

All strings that can be obtained in this way can be evaluated as formulas.

Evaluate all possible formulas, and print the sum of the results.

Constraints

1 \leq |S| \leq 10

All letters in S are digits between 1 and 9, inclusive.

Input

The input is given from Standard Input in the following format:

S

Output

Print the sum of the evaluated value over all possible formulas.

Sample Input 1

125

Sample Output 1

176

There are 4 formulas that can be obtained: 125, 1+25, 12+5 and 1+2+5. When each formula is evaluated,

125

1+25=26

12+5=17

1+2+5=8

Thus, the sum is 125+26+17+8=176.

Sample Input 2

9999999999

Sample Output 2

12656242944


package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func nextLine() string {
	sc.Scan()
	return sc.Text()
}

// var end int
// var slice []string

func main() {
	sc.Split(bufio.ScanWords)

	// slice = strings.Split(nextLine(), "")
	// end = len(slice)

	s := nextLine()

	// sum := 0
	// for i := 1; i < len(s); i++ {
	// 	s1 := s[0:i]
	// 	fmt.Printf("s1=%s ", s1)
	// 	a, _ := strconv.Atoi(s1)
	// 	sum += a
	// 	for j := i + 1; j < len(s); j++ {
	// 		s2 := s[i:j]
	// 		fmt.Printf("s2=%s ", s2)
	// 		b, _ := strconv.Atoi(s2)
	// 		sum += b
	// 	}
	// 	fmt.Println()
	// }

	// fmt.Println(sum)

	// fmt.Println(s)
	// fmt.Println(s[0])
	// fmt.Println(s[0:1])
	// fmt.Println(s[0:2])
	// fmt.Println(s[1:len(s)])
	ans := dfs(0, s)
	fmt.Println(ans)
}

func dfs(sum int, s string) int {
	result := sum
	for i := 1; i < len(s); i++ {
		a, _ := strconv.Atoi(s[0:i])
		result += dfs(sum+a, s[i:len(s)])
	}
	a, _ := strconv.Atoi(s)
	return result + a
}

// func dfs(sum int, s string) int {

// 	if len(s) == 0 {
// 		return sum
// 	}

// if i == len(s)+1 {
// 	return sum
// }

// i番目の後ろに+を挿入する場合
// var sum1 int
// s1, _ := strconv.Atoi(s[0:1])

// fmt.Printf("sum+s1=%d sum=%d s1=%d, s[i:len(s)]=%s\n", sum+s1, sum, s1, s[1:len(s)])
// sum1 += dfs(sum+s1, s[1:len(s)])

// i番目の後ろに+を挿入しない場合
// var sum2 int
// // s2, _ := strconv.Atoi(s[0:len(s)])
// fmt.Printf("sum+s2=%d  sum=%d s2=%d, s[0:len(s)]=%s\n", sum+0, sum, 0, s[0:len(s)])
// sum2 += dfs(sum, s[0:len(s)])

// return sum2
// }


package main

import "fmt"

func main() {
	var n, k, x, y int
	fmt.Scanf("%d\n%d\n%d\n%d\n", &n, &k, &x, &y)

	if n-k > 0 {
		fmt.Println(k*x + (n-k)*y)
	} else {
		fmt.Println(n * x)
	}
}

Score : 100 points

Problem Statement

There is a hotel with the following accommodation fee:

X yen (the currency of Japan) per night, for the first K nights

Y yen per night, for the (K+1)-th and subsequent nights

Tak is staying at this hotel for N consecutive nights.
Find his total accommodation fee.

Constraints

1 \leq N, K \leq 10000

1 \leq Y < X \leq 10000

N,\,K,\,X,\,Y are integers.

Input

The input is given from Standard Input in the following format:

N
K
X
Y

Output

Print Tak's total accommodation fee.

Sample Input 1

5
3
10000
9000

Sample Output 1

48000

The accommodation fee is as follows:

10000 yen for the 1-st night

10000 yen for the 2-nd night

10000 yen for the 3-rd night

9000 yen for the 4-th night

9000 yen for the 5-th night

Thus, the total is 48000 yen.

Sample Input 2

2
3
10000
9000

Sample Output 2

20000


package main

import "fmt"
import "strings"

func main() {
	var w string
	fmt.Scan(&w)

	ws := strings.Split(w, "")
	cns := make(map[string]int)
	for _, ww := range ws {
		cns[ww] += 1
	}

	for _, v := range cns {
		if v%2 != 0 {
			fmt.Println("No")
			return
		}
	}

	fmt.Println("Yes")
}

Score : 200 points

Problem Statement

Let w be a string consisting of lowercase letters.
We will call w beautiful if the following condition is satisfied:

Each lowercase letter of the English alphabet occurs even number of times in w.

You are given the string w. Determine if w is beautiful.

Constraints

1 \leq |w| \leq 100

w consists of lowercase letters (a-z).

Input

The input is given from Standard Input in the following format:

w

Output

Print Yes if w is beautiful. Print No otherwise.

Sample Input 1

abaccaba

Sample Output 1

Yes

a occurs four times, b occurs twice, c occurs twice and the other letters occur zero times.

Sample Input 2

hthth

Sample Output 2

No


package main

import "fmt"

func main() {
	var s string
	fmt.Scan(&s)
	m := make(map[rune]int)
	for _, v := range s {
		m[v]++
	}
	ok := true
	for _, v := range m {
		if v%2 != 0 {
			ok = false
		}
	}
	if ok {
		fmt.Println("Yes")
	} else {
		fmt.Println("No")
	}
}


package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
)

var sc = bufio.NewScanner(os.Stdin)

func nextLine() string {
	sc.Scan()
	return sc.Text()
}

func main() {
	w := []byte(nextLine())
	var w2 []int
	for i := 0; i < len(w); i++ {
		w2 = append(w2, int(w[i]))
	}
	if len(w)%2 != 0 {
		fmt.Println("No")
	} else {
		sort.Sort(sort.IntSlice(w2))
		for i := 0; i < len(w)/2; i++ {
			if w2[2*i] != w2[2*i+1] {
				fmt.Println("No")
				return
			}
		}
		fmt.Println("Yes")
	}
}


package main

import (
  "bufio"
  "container/heap"
  "fmt"
  "os"
  "sort"
  "strconv"
  "strings"
)

const INF int = 100000000

func main() {
  input := Input{bufio.NewReaderSize(os.Stdin,1000000)}
  n := input.NextInt()
  x := append(append([]int{0},input.NextIntArray()...),2100000000)
  l := input.NextInt()
  q := input.NextInt()
  u := make([]int,n+1)
  g := NewGraph(n+1)
  for i:=1;i<n+1;i++ {
    j := sort.Search(n+2,func(j int) bool { return x[i]+l < x[j] })
    if u[i] == 0 { u[i] = i }
    if u[j-1] == 0 { u[j-1] = u[i] }
    g.Add(i,j-1,1)
  }
  c := make([][]int,n+1)
  for i:=1;i<n+1;i++ {
    if u[i] == i { c[i] = g.Dijkstra(i) }
  }
  for k:=0;k<q;k++ {
    a,b := input.NextInts()
    if a > b { a,b = b,a }
    fmt.Println(c[u[a]][b]-c[u[a]][a])
  }
}

type Item struct { pos,cost,idx int }
type PriorityQueue []*Item
func(pq PriorityQueue) Len() int { return len(pq) }
func(pq PriorityQueue) Less(i,j int) bool { return pq[i].cost < pq[j].cost }
func(pq PriorityQueue) Swap(i,j int) {
  pq[i],pq[j] = pq[j],pq[i]
  pq[i].idx,pq[j].idx = i,j
}
func(pq *PriorityQueue) Push(x interface{}) {
  n := len(*pq)
  item := x.(*Item)
  item.idx = n
  *pq = append(*pq,item)
}
func(pq *PriorityQueue) Pop() interface{} {
  old := *pq
  n := len(old)
  item := old[n-1]
  item.idx = -1
  *pq = old[0:n-1]
  return item
}

type Edge struct { to,cost int }
type Graph [][]Edge
func NewGraph(n int) Graph { return make([][]Edge,n) }
func(g Graph) AddEdge(from int,e Edge) { g[from] = append(g[from],e) }
func(g Graph) Add(from,to,cost int) { g.AddEdge(from,Edge{to,cost}) }
func(g Graph) Dijkstra(start int) []int {
  n := len(g)
  c := make([]int,n)
  for i:=0;i<n;i++ { c[i] = INF }
  var pq PriorityQueue
  heap.Init(&pq)
  heap.Push(&pq,&Item{pos:start,cost:0})
  c[start] = 0
  for pq.Len() > 0 {
    s := heap.Pop(&pq).(*Item)
    if s.cost > c[s.pos] { continue }
    for _, e := range g[s.pos] {
      if c[e.to] > s.cost+e.cost {
        c[e.to] = s.cost+e.cost
        heap.Push(&pq,&Item{pos:e.to,cost:c[e.to]})
      }
    }
  }
  for i:=n-2;i>-1;i-- {
    if c[i] == INF { c[i] = c[i+1] }
  }
  return c
}

type Input struct { reader *bufio.Reader }
func(i *Input) NextLine() string {
  var buffer []byte
  for {
    line,isPrefix,err := i.reader.ReadLine()
    if err != nil { panic(err) }
    buffer = append(buffer,line...)
    if !isPrefix { break }
  }
  return string(buffer)
}
func(i *Input) NextInt() int {
  n,_ := strconv.Atoi(i.NextLine())
  return n
}
func(i *Input) NextInts() (int,int) {
  s := strings.Split(i.NextLine()," ")
  x,_ := strconv.Atoi(s[0])
  y,_ := strconv.Atoi(s[1])
  return x,y
}
func(i *Input) NextIntArray() []int {
  s := strings.Split(i.NextLine()," ")
  a := make([]int,len(s))
  for i:=0;i<len(s);i++ { a[i],_ = strconv.Atoi(s[i]) }
  return a
}

Score : 700 points

Problem Statement

N hotels are located on a straight line. The coordinate of the i-th hotel (1 \leq i \leq N) is x_i.

Tak the traveler has the following two personal principles:

He never travels a distance of more than L in a single day.

He never sleeps in the open. That is, he must stay at a hotel at the end of a day.

You are given Q queries. The j-th (1 \leq j \leq Q) query is described by two distinct integers a_j and b_j.
For each query, find the minimum number of days that Tak needs to travel from the a_j-th hotel to the b_j-th hotel following his principles.
It is guaranteed that he can always travel from the a_j-th hotel to the b_j-th hotel, in any given input.

Constraints

2 \leq N \leq 10^5

1 \leq L \leq 10^9

1 \leq Q \leq 10^5

1 \leq x_i < x_2 < ... < x_N \leq 10^9

x_{i+1} - x_i \leq L

1 \leq a_j,b_j \leq N

a_j \neq b_j

N,\,L,\,Q,\,x_i,\,a_j,\,b_j are integers.

Partial Score

200 points will be awarded for passing the test set satisfying N \leq 10^3 and Q \leq 10^3.

Input

The input is given from Standard Input in the following format:

N
x_1 x_2 ... x_N
L
Q
a_1 b_1
a_2 b_2
:
a_Q b_Q

Output

Print Q lines.
The j-th line (1 \leq j \leq Q) should contain the minimum number of days that Tak needs to travel from the a_j-th hotel to the b_j-th hotel.

Sample Input 1

9
1 3 6 13 15 18 19 29 31
10
4
1 8
7 3
6 7
8 5

Sample Output 1

4
2
1
2

For the 1-st query, he can travel from the 1-st hotel to the 8-th hotel in 4 days, as follows:

Day 1: Travel from the 1-st hotel to the 2-nd hotel. The distance traveled is 2.

Day 2: Travel from the 2-nd hotel to the 4-th hotel. The distance traveled is 10.

Day 3: Travel from the 4-th hotel to the 7-th hotel. The distance traveled is 6.

Day 4: Travel from the 7-th hotel to the 8-th hotel. The distance traveled is 10.


package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}

func getNextUint64(scanner *bufio.Scanner) uint64 {
	i, _ := strconv.ParseUint(getNextString(scanner), 10, 64)
	return i
}

func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}

func main() {
	fp := os.Stdin
	wfp := os.Stdout

	if os.Getenv("MASPY") == "ますピ" {
		fp, _ = os.Open(os.Getenv("BEET_THE_HARMONY_OF_PERFECT"))
	}
	if os.Getenv("MASPYPY") == "ますピッピ" {
		wfp, _ = os.Create(os.Getenv("NGTKANA_IS_GENIUS10"))
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(wfp)

	s := getNextString(scanner)
	n := len(s)
	m := map[byte]int{
		'N': 0,
		'W': 0,
		'S': 0,
		'E': 0,
	}

	for i := 0; i < n; i++ {
		m[s[i]] = 1
	}

	if m['S']^m['N'] == 1 {
		fmt.Println("No")
		return
	}
	if m['E']^m['W'] == 1 {
		fmt.Println("No")
		return
	}
	fmt.Println("Yes")
	writer.Flush()
}

Score : 200 points

Problem Statement

Snuke lives on an infinite two-dimensional plane. He is going on an N-day trip.
At the beginning of Day 1, he is at home. His plan is described in a string S of length N.
On Day i(1 ≦ i ≦ N), he will travel a positive distance in the following direction:

North if the i-th letter of S is N

West if the i-th letter of S is W

South if the i-th letter of S is S

East if the i-th letter of S is E

He has not decided each day's travel distance. Determine whether it is possible to set each day's travel distance so that he will be back at home at the end of Day N.

Constraints

1 ≦ | S | ≦ 1000

S consists of the letters N, W, S, E.

Input

The input is given from Standard Input in the following format:

S

Output

Print Yes if it is possible to set each day's travel distance so that he will be back at home at the end of Day N. Otherwise, print No.

Sample Input 1

SENW

Sample Output 1

Yes

If Snuke travels a distance of 1 on each day, he will be back at home at the end of day 4.

Sample Input 2

NSNNSNSN

Sample Output 2

Yes

Sample Input 3

NNEW

Sample Output 3

No

Sample Input 4

W

Sample Output 4

No


package main

import (
	"fmt"
	"bufio"
	"os"
	"strconv"
)

//=====I/O=====

var (
	sc = bufio.NewScanner(os.Stdin)
	wr = bufio.NewWriter(os.Stdout)
)

func scanInt() int {
	sc.Scan()
	a,_ := strconv.Atoi(sc.Text())
	return a
}

func scanInt64() int64 {
	sc.Scan()
	a,_ := strconv.ParseInt(sc.Text(),10,64)
	return a
}

func scanInts(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ { res[i] = scanInt() }
	return res
}

func scanText() string {
	sc.Scan()
	return sc.Text()
}

func printInts(a ...int) {
	for i, e := range a {
		fmt.Fprint(wr, e)
		if i != len(a)-1 { fmt.Fprint(wr, " ") }
	}
	fmt.Fprintln(wr)
	wr.Flush()
}

//=====main=====

func main() {
	sc.Split(bufio.ScanWords)

	n := scanInt()
	as := scanInts(n)
	as = append(as,0)

	ans := 0

	for i := 0; i < n; i++ {
		if as[i]!=as[i+1] {
			ans+=as[i]/2
		} else {
			ans+=as[i]
			as[i+1]=0
		}
	}

	fmt.Println(ans)

}

func abs(a int) int {
	if a<0 {
		return -a
	}
	return a
}

func min(a ...int) int {
	res := a[0]
	for i := 1; i < len(a); i++ {
		if res > a[i] { res = a[i] }
	}
	return res
}

func max(a ...int) int {
	res := a[0]
	for i := 1; i < len(a); i++ {
		if res < a[i] { res = a[i] }
	}
	return res
}

Score : 400 points

Problem Statement

Snuke has a large collection of cards. Each card has an integer between 1 and N, inclusive, written on it.
He has A_i cards with an integer i.

Two cards can form a pair if the absolute value of the difference of the integers written on them is at most 1.

Snuke wants to create the maximum number of pairs from his cards, on the condition that no card should be used in multiple pairs. Find the maximum number of pairs that he can create.

Constraints

1 ≦ N ≦ 10^5

0 ≦ A_i ≦ 10^9 (1 ≦ i ≦ N)

All input values are integers.

Input

The input is given from Standard Input in the following format:

N
A_1
:
A_N

Output

Print the maximum number of pairs that Snuke can create.

Sample Input 1

4
4
0
3
2

Sample Output 1

4

For example, Snuke can create the following four pairs: (1,1),(1,1),(3,4),(3,4).

Sample Input 2

8
2
0
1
6
0
8
2
1

Sample Output 2

9


package main

import (
	"fmt"
	"bufio"
	"os"
	"strconv"
)

//=====I/O=====

var (
	sc = bufio.NewScanner(os.Stdin)
	wr = bufio.NewWriter(os.Stdout)
)

func scanInt() int {
	sc.Scan()
	a,_ := strconv.Atoi(sc.Text())
	return a
}

func scanInt64() int64 {
	sc.Scan()
	a,_ := strconv.ParseInt(sc.Text(),10,64)
	return a
}

func scanInts(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ { res[i] = scanInt() }
	return res
}

func scanText() string {
	sc.Scan()
	return sc.Text()
}

func printInts(a ...int) {
	for i, e := range a {
		fmt.Fprint(wr, e)
		if i != len(a)-1 { fmt.Fprint(wr, " ") }
	}
	fmt.Fprintln(wr)
	wr.Flush()
}

//=====main=====

func main() {
	sc.Split(bufio.ScanWords)

	n := scanInt()
	as := scanInts(n)
	as = append(as,0)

	ans := 0

	for i := 0; i < n; i++ {
		if as[i]%2<=abs(as[i]-as[i+1]) {
			ans+=as[i]/2
		} else {
			ans+=min(as[i],as[i+1])
			as[i+1]=0
		}
	}

	fmt.Println(ans)

}

func abs(a int) int {
	if a<0 {
		return -a
	}
	return a
}

func min(a ...int) int {
	res := a[0]
	for i := 1; i < len(a); i++ {
		if res > a[i] { res = a[i] }
	}
	return res
}

func max(a ...int) int {
	res := a[0]
	for i := 1; i < len(a); i++ {
		if res < a[i] { res = a[i] }
	}
	return res
}


package main

import (
  "bufio"
  "os"
  "strconv"
  "strings"
  "fmt"
)

var reader = bufio.NewReaderSize(os.Stdin, 1000000)
var writer = bufio.NewWriter(os.Stdout)
func NextLine() string {
  var line, buffer []byte
  var isPrefix bool = true
  var err error
  for isPrefix {
    line, isPrefix, err = reader.ReadLine()
    if err != nil { panic(err) }
    buffer = append(buffer, line...)
  }
  return string(buffer)
}
func NextInt() int {
  var n int
  n, _ = strconv.Atoi(NextLine())
  return n
}
func NextIntVec() []int {
  L := strings.Split(NextLine(), " ")
  N := make([]int, len(L))
  for i := range N {
    N[i], _ = strconv.Atoi(L[i])
  }
  return N
}
func Write(s interface{}) {
  fmt.Fprintln(writer, s)
}
func Output() {
  _ = writer.Flush()
}

func Min(a, b int) int {
  if a < b { return a }
  return b
}

func main() {
  N := NextInt()
  cnt := 0
  A := make([]int, N)
  for i := range A {
    A[i] = NextInt()
  }
  for i, _ := range A {
    if i < N - 1 && 0 < A[i] % 2 {
      cnt += 1
      A[i]--
      A[i + 1]--
    }
    cnt += A[i] / 2
  }
  Write(cnt)
  Output()
}


package main

import (
    "bufio"
    "fmt"
    "math"
    "os"
    "sort"
    "strconv"
    "strings"
)

func readQuestion() []int {

    bufio := bufio.NewReader(os.Stdin)
    l, _ := bufio.ReadString('\n')
    n, _ := strconv.Atoi(strings.Trim(l, "\n"))
    cards := make([]int, n)
    for i := 0; i < n; i++ {
        l, _ = bufio.ReadString('\n')
        n, _ := strconv.Atoi(strings.Trim(l, "\n"))
        cards[i] = n
    }
    return cards
}

func solve(vals []int) int {

    sorted := make([]int, len(vals))
    copy(sorted, vals)
    sort.Ints(sorted)

    pos := make(map[int]int)
    for i, val := range sorted {
        pos[val] = i
    }
    odds := 0
    for i, val := range vals {
        pos1 := i
        pos2 := pos[val]
        if int(math.Abs(float64(pos1)-float64(pos2)))%2 == 1 {
            odds++
        }
    }

    return odds / 2
}

func main() {
    vals := readQuestion()
    ans := solve(vals)
    fmt.Printf("%v\n", ans)
}

Score : 600 points

Problem Statement

Snuke got an integer sequence of length N from his mother, as a birthday present. The i-th (1 ≦ i ≦ N) element of the sequence is a_i. The elements are pairwise distinct.
He is sorting this sequence in increasing order.
With supernatural power, he can perform the following two operations on the sequence in any order:

Operation 1: choose 2 consecutive elements, then reverse the order of those elements.

Operation 2: choose 3 consecutive elements, then reverse the order of those elements.

Snuke likes Operation 2, but not Operation 1. Find the minimum number of Operation 1 that he has to perform in order to sort the sequence in increasing order.

Constraints

1 ≦ N ≦ 10^5

0 ≦ A_i ≦ 10^9

If i ≠ j, then A_i ≠ A_j.

All input values are integers.

Input

The input is given from Standard Input in the following format:

N
A_1
:
A_N

Output

Print the minimum number of times Operation 1 that Snuke has to perform.

Sample Input 1

4
2
4
3
1

Sample Output 1

1

The given sequence can be sorted as follows:

First, reverse the order of the last three elements. The sequence is now: 2,1,3,4.

Then, reverse the order of the first two elements. The sequence is now: 1,2,3,4.

In this sequence of operations, Operation 1 is performed once. It is not possible to sort the sequence with less number of Operation 1, thus the answer is 1.

Sample Input 2

5
10
8
5
3
2

Sample Output 2

0


package main

import (
    "bufio"
    "fmt"
    "os"
    "sort"
    "strconv"
    "strings"
)

func readQuestion() ([]int, []int) {

    bufio := bufio.NewReader(os.Stdin)
    l, _ := bufio.ReadString('\n')
    n, _ := strconv.Atoi(strings.Trim(l, "\n"))
    cards1 := make([]int, (n+1)/2)
    cards2 := make([]int, n/2)
    for i := 0; i < n; i++ {
        l, _ = bufio.ReadString('\n')
        n, _ := strconv.Atoi(strings.Trim(l, "\n"))
        if i%2 == 0 {
            cards1[i/2] = n
        } else {
            cards2[i/2] = n
        }
    }
    return cards1, cards2
}

func bubbleSort(vals []int, start int, step int) int {

    count := 0
    v2End := start + (len(vals)-start-1)/step*step
    for start+step <= v2End {
        //fmt.Printf("%v, start=%v, end=%v\n", vals, start, v2End)
        nextV2End := start
        for i := start; i+step <= v2End; i += step {
            //fmt.Printf(" v2End=%v check %v %v\n", v2End, i, i+step)
            v1 := vals[i]
            v2 := vals[i+step]
            if v1 > v2 {
                //fmt.Printf("swap\n")
                vals[i], vals[i+step] = v2, v1
                count++
                nextV2End = i
            }
        }
        v2End = nextV2End
    }

    //     i
    // 1 2 5 4 6 7
    //     4 5
    return count
}

func solve(vals1, vals2 []int) int {

    sort.Ints(vals1)
    sort.Ints(vals2)

    // append 1 and 2
    vals := []int{}
    for i := 0; i < len(vals2); i++ {
        vals = append(vals, vals1[i])
        vals = append(vals, vals2[i])
    }
    if len(vals1) > len(vals2) {
        vals = append(vals, vals1[len(vals1)-1])
    }
    //fmt.Printf("%v\n", vals1)
   //fmt.Printf("%v\n", vals)

    ans := bubbleSort(vals, 0, 1)
    //fmt.Printf("%v\n", vals)
    return ans
}

func main() {
    vals1, vals2 := readQuestion()
    ans := solve(vals1, vals2)
    fmt.Printf("%v\n", ans)
}


package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"math"
	"os"
	"strconv"
)

const (
	initialBufSize = 10000
	maxBufSize     = 1000000
	mod            = 1e9 + 7
)

var (
	sc *bufio.Scanner = func() *bufio.Scanner {
		sc := bufio.NewScanner(os.Stdin)
		buf := make([]byte, initialBufSize)
		sc.Buffer(buf, maxBufSize)
		sc.Split(bufio.ScanWords)
		return sc
	}()
)

func main() {
	N := getInt()
	result := 0
	for i := 1; i <= N; i++ {
		result += i
	}
	fmt.Println(result)
}

type Graph struct {
	n     int
	edges [][]int
}

func NewGraph(n int) *Graph {
	g := &Graph{
		n:     n,
		edges: make([][]int, n),
	}
	return g
}

func (g *Graph) AddEdge(u, v int) {
	g.edges[v] = append(g.edges[v], u)
	g.edges[u] = append(g.edges[u], v)
}

func dfs(c int, edges [][]int, visited map[int]struct{}) {
	visited[c] = struct{}{}

	for _, v := range edges[c] {
		_, flag := visited[v]
		if flag {
			continue
		}
		dfs(v, edges, visited)
	}
}

func bfs(c int, graph *Graph) {
	next := make([]int, 0)
	next = append(next, c)
	visited := make(map[int]struct{})

	for ; len(next) != 0; {
		u := next[0]
		next = next[1:]
		visited[u] = struct{}{}

		for _, v := range graph.edges[u] {
			_, flag := visited[v]
			if flag {
				continue
			}

			// なにか処理

			next = append(next, v)
		}
	}
}

func getInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func getIntArray(n int) []int {
	array := make([]int, n)
	for i := 0; i < n; i++ {
		array[i] = getInt()
	}
	return array
}

func getString() string {
	sc.Scan()
	return sc.Text()
}

func getStringArray(n int) []string {
	array := make([]string, n)
	for i := 0; i < n; i++ {
		array[i] = getString()
	}
	return array
}

func abs(a int) int {
	return int(math.Abs(float64(a)))
}

func pow(p, q int) int {
	return int(math.Pow(float64(p), float64(q)))
}

func powMod(n, p int) int {
	if p == 0 {
		return 1
	} else if p%2 == 0 {
		t := powMod(n, p/2)
		return calcMod(t * t)
	} else {
		return calcMod(n * powMod(n, p-1))
	}
}

func min(nums ...int) int {
	if len(nums) == 0 {
		panic("funciton min() requires at least one argument.")
	}
	res := nums[0]
	for i := 0; i < len(nums); i++ {
		res = int(math.Min(float64(res), float64(nums[i])))
	}
	return res
}

func max(nums ...int) int {
	if len(nums) == 0 {
		panic("funciton max() requires at least one argument.")
	}
	res := nums[0]
	for i := 0; i < len(nums); i++ {
		res = int(math.Max(float64(res), float64(nums[i])))
	}
	return res
}

func strSearch(a []string, b string) bool {
	for i := 0; i < len(a); i++ {
		if a[i] == b {
			return true
		}
	}
	return false
}

func printIntArray(array []int) {
	strArray := fmt.Sprint(array)
	fmt.Println(strArray[1 : len(strArray)-1])
}

func calcMod(x int) int {
	return x % mod
}

func reverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}
	return string(runes)
}

func isPrime(n int) bool {
	if n < 2 {
		return false
	} else if n == 2 {
		return true
	} else if n % 2 == 0 {
		return false
	}

	sqrtN := int(math.Sqrt(float64(n)))
	for i := 3; i <= sqrtN; i += 2 {
		if n % i == 0 {
			return false
		}
	}

	return true
}

func contains(s []int, e int) bool {
	for _, v := range s {
		if e == v {
			return true
		}
	}
	return false
}

func makeRange(min, max int) []int {
	a := make([]int, max-min+1)
	for i := range a {
		a[i] = min + i
	}
	return a
}

func powerset2(nums []int) [][]int {
	length := int(math.Pow(2, float64(len(nums))))
	result := make([][]int, length)

	index := 0
	result[index] = []int{}
	index++

	for _, n := range nums {
		max := index
		for i := 0; i < max; i++ {
			result[index] = copyAndAppend(result[i], n)
			index++
		}
	}

	return result
}

func copyAndAppend(nums []int, n int) []int {
	dst := make([]int, len(nums)+1)
	copy(dst, nums)
	dst[len(nums)] = n
	return dst
}

func calcGcd(x, y int) int {
	if y == 0 {
		return x
	} else if x >= y {
		return calcGcd(y, x % y)
	} else {
		return calcGcd(x, y % x)
	}
}

func getDivisor(n int) []int {
	var divisor []int
	divisor = append(divisor, 1)
	if n != 1 {
		divisor = append(divisor, n)
	}

	sqrt := int(math.Sqrt(float64(n)))
	for i := 2; i <= sqrt; i++ {
		if n % i == 0 {
			divisor = append(divisor, i)
			divisor = append(divisor, n/i)
		}
	}
	return divisor
}

type intHeap []int

func (h intHeap) Len() int {
	return len(h)
}

func (h intHeap) Less(i, j int) bool {
	return h[i] > h[j]
}

func (h intHeap) Swap(i, j int) {
	h[i], h[j] = h[j], h[i]
}

func (h *intHeap) Push(x interface{}) {
	*h = append(*h, x.(int))
}

func (h *intHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

func initHeap() *intHeap {
	ih := &intHeap{}
	heap.Init(ih)
	return ih
}

func (h *intHeap) pushHeap(n int) {
	heap.Push(h, n)
}

func (h *intHeap) popHeap() int {
	return heap.Pop(h).(int)
}

func factMod(n int) int {
	value := 1
	for ; n > 1; n-- {
		value = calcMod(value * n)
	}
	return value
}

func combinationMod(n, k int) int {
	factN := factMod(n)
	factK := factMod(k)
	factNK := factMod(n - k)
	factKR := powMod(factK, mod - 2)
	factNKR := powMod(factNK, mod - 2)
	return calcMod(factN * calcMod(factKR * factNKR))
}

func primeFactors(n int) [] int {
	factors := make([]int, 0)
	i := 2
	for i * i <= n {
		r := n % i
		if r != 0 {
			i += 1
		} else if r == 0 {
			n /= i
			factors = append(factors, i)
		}
	}
	if n > 1 {
		factors = append(factors, n)
	}
	return factors
}

Score : 100 points

Problem Statement

There are N children in AtCoder Kindergarten. Mr. Evi will arrange the children in a line, then give 1 candy to the first child in the line, 2 candies to the second child, ..., N candies to the N-th child. How many candies will be necessary in total?

Constraints

1≦N≦100

Input

The input is given from Standard Input in the following format:

N

Output

Print the necessary number of candies in total.

Sample Input 1

3

Sample Output 1

6

The answer is 1+2+3=6.

Sample Input 2

10

Sample Output 2

55

The sum of the integers from 1 to 10 is 55.

Sample Input 3

1

Sample Output 3

1

Only one child. The answer is 1 in this case.


package main

import "fmt"

func main(){
  var N int
  var n int = 1
  var sum int = 0
  fmt.Scan(&N)
  for n <= N {
    sum = sum + n
    n = n + 1
  }
  fmt.Println(sum)
}


package main

import (
	"fmt"
	"strings"
)

func main() {
	var s string
	fmt.Scan(&s)
	ls := strings.Split(s, "")

	result := []string{}
	for i, x := range ls {
		if x != "B" {
			result = append(result, x)
		} else if i != 0 && x == "B" {
			result = result[:i-1]
		}
	}
	r := strings.Join(result, "")
	fmt.Println(r)
}

Score : 200 points

Problem Statement

Sig has built his own keyboard. Designed for ultimate simplicity, this keyboard only has 3 keys on it: the 0 key, the 1 key and the backspace key.

To begin with, he is using a plain text editor with this keyboard. This editor always displays one string (possibly empty). Just after the editor is launched, this string is empty. When each key on the keyboard is pressed, the following changes occur to the string:

The 0 key: a letter 0 will be inserted to the right of the string.

The 1 key: a letter 1 will be inserted to the right of the string.

The backspace key: if the string is empty, nothing happens. Otherwise, the rightmost letter of the string is deleted.

Sig has launched the editor, and pressed these keys several times. You are given a string s, which is a record of his keystrokes in order. In this string, the letter 0 stands for the 0 key, the letter 1 stands for the 1 key and the letter B stands for the backspace key. What string is displayed in the editor now?

Constraints

1 ≦ |s| ≦ 10 (|s| denotes the length of s)

s consists of the letters 0, 1 and B.

The correct answer is not an empty string.

Input

The input is given from Standard Input in the following format:

s

Output

Print the string displayed in the editor in the end.

Sample Input 1

01B0

Sample Output 1

00

Each time the key is pressed, the string in the editor will change as follows: 0, 01, 0, 00.

Sample Input 2

0BB1

Sample Output 2

1

Each time the key is pressed, the string in the editor will change as follows: 0, (empty), (empty), 1.


package main

import (
	"fmt"
	"strings"
)

func main() {
	var s string
	fmt.Scan(&s)

	ss := strings.Split(s, "")

	r := []string{}
	for i, s := range ss {
		if "B" == s {
			r[i-1] = ""
		}
		r = append(r, s)
	}

	strings.Join(r, "")
	fmt.Print(r)
}


package main

import "fmt"

func main(){
	var s string

	/*入力を受け取る*/
	fmt.Scan(&s)

	/*入力をstring→文字の配列*/
	sRune := []rune(s)
	size := len(s)

	/*空の文字列*/
	s2 := make([]string, size+1)
	j := 0;

	for i:=0; i<size; i++{
		switch text := string(sRune[i]); text{
		case "1":
			s2[j]=string(sRune[i])
			j++

		case "0":
			s2[j]=string(sRune[i])
			j++

		case "B":
			if j>0{
				j--
			}

		default:

		}
	}

	for i:= 0; i < j; i++{
		fmt.Printf(s2[i])
	}

	fmt.Printf("\n")

}


package main

import (
	"fmt"
	"math"
)

func main() {
	var n int
	fmt.Scan(&n)

	a := make([]float64, n)
	sum := 0.0
	for i := 0; i < n; i++ {
		fmt.Scan(&a[i])
		sum += a[i]
	}

	ans := 0
	m := round(sum / float64(n))
	for i := 0; i < n; i++ {
		ans += int(math.Pow(math.Abs(m-a[i]), 2))
	}
	fmt.Println(ans)
}

func round(f float64) float64 {
	return math.Floor(f + .5)
}

Score : 200 points

Problem Statement

Evi has N integers a_1,a_2,..,a_N. His objective is to have N equal integers by transforming some of them.

He may transform each integer at most once. Transforming an integer x into another integer y costs him (x-y)^2 dollars. Even if a_i=a_j (i≠j), he has to pay the cost separately for transforming each of them (See Sample 2).

Find the minimum total cost to achieve his objective.

Constraints

1≦N≦100

-100≦a_i≦100

Input

The input is given from Standard Input in the following format:

N
a_1 a_2 ... a_N

Output

Print the minimum total cost to achieve Evi's objective.

Sample Input 1

2
4 8

Sample Output 1

8

Transforming the both into 6s will cost (4-6)^2+(8-6)^2=8 dollars, which is the minimum.

Sample Input 2

3
1 1 3

Sample Output 2

3

Transforming the all into 2s will cost (1-2)^2+(1-2)^2+(3-2)^2=3 dollars. Note that Evi has to pay (1-2)^2 dollar separately for transforming each of the two 1s.

Sample Input 3

3
4 2 5

Sample Output 3

5

Leaving the 4 as it is and transforming the 2 and the 5 into 4s will achieve the total cost of (2-4)^2+(5-4)^2=5 dollars, which is the minimum.

Sample Input 4

4
-100 -100 -100 -100

Sample Output 4

0

Without transforming anything, Evi's objective is already achieved. Thus, the necessary cost is 0.


package main

import (
	"fmt"
)

func main() {
	var n int

	fmt.Scan(&n)

	a := make([]int, n)

	for i := 0; i < n; i++ {
		fmt.Scan(&a[i])
	}

	var min int
	first := true

	for i := -100; i <= 100; i++ {
		var tmp int
		for j := 0; j < n; j++ {
			tmp += (i - a[j]) * (i - a[j])
		}
		if first || tmp < min {
			min = tmp
			first = false
		}
	}

	fmt.Println(min)

}


package main

import "fmt"

type Pair struct{
    fst int
    snd int
}

func main() {
    var s string
    ans := Pair{-1, -1}

    fmt.Scan(&s)
    for i:=0; i<len(s)-2; i++ {
        if s[i] == s[i+1]  || s[i+1] == s[i+2] || s[i] == s[i+2] {
            ans = Pair{i+1, i+3}
            break
        }
    }

    fmt.Println(ans.fst, ans.snd)
}

Score : 400 points

Problem Statement

Given a string t, we will call it unbalanced if and only if the length of t is at least 2, and more than half of the letters in t are the same. For example, both voodoo and melee are unbalanced, while neither noon nor a is.

You are given a string s consisting of lowercase letters. Determine if there exists a (contiguous) substring of s that is unbalanced. If the answer is positive, show a position where such a substring occurs in s.

Constraints

2 ≦ |s| ≦ 10^5

s consists of lowercase letters.

Partial Score

200 points will be awarded for passing the test set satisfying 2 ≦ N ≦ 100.

Input

The input is given from Standard Input in the following format:

s

Output

If there exists no unbalanced substring of s, print -1 -1.

If there exists an unbalanced substring of s, let one such substring be s_a s_{a+1} ... s_{b} (1 ≦ a < b ≦ |s|), and print a b. If there exists more than one such substring, any of them will be accepted.

Sample Input 1

needed

Sample Output 1

2 5

The string s_2 s_3 s_4 s_5 = eede is unbalanced. There are also other unbalanced substrings. For example, the output 2 6 will also be accepted.

Sample Input 2

atcoder

Sample Output 2

-1 -1

The string atcoder contains no unbalanced substring.


package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"strconv"
)

//Util
func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func maxInt(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func minInt(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

func absInt(a int) int {
	if a >= 0 {
		return a
	} else {
		return -a
	}
}

func absFloat64(a float64) float64 {
	if a >= 0 {
		return a
	} else {
		return -a
	}
}

func maxFloat64(a, b float64) float64 {
	if a > b {
		return a
	} else {
		return b
	}
}

func minFloat64(a, b float64) float64 {
	if a > b {
		return b
	} else {
		return a
	}
}

func str2Int(s string) int {
	n, _ := strconv.Atoi(s)
	return n
}

func reverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}
	return string(runes)
}

func pow(p, q int) int {
	return int(math.Pow(float64(p), float64(q)))
}

func isPrime(x int) bool {
	if x == 1 {
		return false
	}
	if x == 2 {
		return true
	}
	if x%2 == 0 {
		return false
	}

	b := true
	rootx := int(math.Sqrt(float64(x)))
	i := 3
	for i <= rootx {
		if x%i == 0 {
			b = false
			break
		}
		i += 2
	}
	return b
}

func PrimeFactors(n int) (pfs []int) {
	// Get the number of 2s that divide n
	for n%2 == 0 {
		pfs = append(pfs, 2)
		n = n / 2
	}

	// n must be odd at this point. so we can skip one element
	// (note i = i + 2)
	for i := 3; i*i <= n; i = i + 2 {
		// while i divides n, append i and divide n
		for n%i == 0 {
			pfs = append(pfs, i)
			n = n / i
		}
	}

	// This condition is to handle the case when n is a prime number
	// greater than 2
	if n > 2 {
		pfs = append(pfs, n)
	}

	return
}

//Main
const (
	initialBufSize = 10000
	maxBufSize     = 1000000
	mod            = 1e9 + 7
)

var (
	sc *bufio.Scanner = func() *bufio.Scanner {
		sc := bufio.NewScanner(os.Stdin)
		buf := make([]byte, initialBufSize)
		sc.Buffer(buf, maxBufSize)
		return sc
	}()
)

var a, b int

func main() {
	sc.Split(bufio.ScanWords)

	a, b = nextInt(), nextInt()

	if a <= 0 && b >= 0 {
		fmt.Println("Zero")
	} else if a > 0 {
		fmt.Println("Positive")
		return
	} else if b < 0 {
		if (maxInt(0, b)-a)%2 == 0 {
			fmt.Println("Positive")
		} else {
			fmt.Println("Negative")
		}
	}
}

Problem Statement

You are given two integers a and b (a≤b). Determine if the product of the integers a, a+1, …, b is positive, negative or zero.

Constraints

a and b are integers.

-10^9≤a≤b≤10^9

Partial Score

In test cases worth 100 points, -10≤a≤b≤10.

Input

The input is given from Standard Input in the following format:

a b

Output

If the product is positive, print Positive. If it is negative, print Negative. If it is zero, print Zero.

Sample Input 1

1 3

Sample Output 1

Positive

1×2×3=6 is positive.

Sample Input 2

-3 -1

Sample Output 2

Negative

(-3)×(-2)×(-1)=-6 is negative.

Sample Input 3

-1 1

Sample Output 3

Zero

(-1)×0×1=0.


///
// File:  a.go
// Author: ymiyamoto
//
// Created on Sun Mar 25 19:37:08 2018
//
package main

import (
	"fmt"
)

var a, b int

func main() {
	fmt.Scan(&a, &b)
	if 0 < a {
		fmt.Println("Positive")
	} else if b < 0 {
		if (-a+b+1)%2 == 0 {
			fmt.Println("Positive")
		} else {
			fmt.Println("Negative")
		}
	} else {
		fmt.Println("Zero")
	}
}


// 隣り合うのをL以上になるようにくっつけていきたいね 一箇所でもみつければあとは隣接してるのをくっつけていきたいね
// -> てんでダメでした
// よくよくみたらおかしいところ 端から切り離す感じにするようにした
// -> なぜかWA
// 3つ並んでる総和がL未満なら見込み0ってことか
// -> そういうことではない

package main

import "fmt"

func main() {
	var N, L int
	fmt.Scan(&N, &L)
	A := make([]int, N)
	for i := 0; i < N; i++ {
		fmt.Scan(&A[i])
	}

	idx := -1
	for i := 1; i < N; i++ {
		if A[i-1]+A[i] >= L {
			idx = i
			break
		}
	}

	if idx == -1 {
		fmt.Println("Impossible")
		return
	}
	P := []int{}
	for i := N - 1; i > idx; i-- {
		P = append(P, i)
	}
	for i := 1; i < idx; i++ {
		P = append(P, i)
	}
	P = append(P, idx)
	fmt.Println("Possible")
	for _, p := range P {
		fmt.Println(p)
	}
}

// 10 4
// 2 1 1 4 2 3 1 2 1 2

// 5 3
// 1 1 3 1 1

// 5 5
// 1 1 3 2 1

Problem Statement

We have N pieces of ropes, numbered 1 through N. The length of piece i is a_i.

At first, for each i (1≤i≤N-1), piece i and piece i+1 are tied at the ends, forming one long rope with N-1 knots. Snuke will try to untie all of the knots by performing the following operation repeatedly:

Choose a (connected) rope with a total length of at least L, then untie one of its knots.

Is it possible to untie all of the N-1 knots by properly applying this operation? If the answer is positive, find one possible order to untie the knots.

Constraints

2≤N≤10^5

1≤L≤10^9

1≤a_i≤10^9

All input values are integers.

Input

The input is given from Standard Input in the following format:

N L
a_1 a_2 ... a_n

Output

If it is not possible to untie all of the N-1 knots, print Impossible.

If it is possible to untie all of the knots, print Possible, then print another N-1 lines that describe a possible order to untie the knots. The j-th of those N-1 lines should contain the index of the knot that is untied in the j-th operation. Here, the index of the knot connecting piece i and piece i+1 is i.

If there is more than one solution, output any.

Sample Input 1

3 50
30 20 10

Sample Output 1

Possible
2
1

If the knot 1 is untied first, the knot 2 will become impossible to untie.

Sample Input 2

2 21
10 10

Sample Output 2

Impossible

Sample Input 3

5 50
10 20 30 40 50

Sample Output 3

Possible
1
2
3
4

Another example of a possible solution is 3, 4, 1, 2.


package main

import (
	"fmt"
	"bufio"
	"os"
	"strconv"
)

const INF int = 1e9
const LINF int64 = 1e9
const MOD int = INF + 7

func main() {
	next := NewScanner()
	N, L := next.Int(), next.Int()
	a := make([]int, N)
	for i := 0; i < N; i++ {
		a[i] = next.Int()
	}

	tmp := 0
	for i := 1; i < N; i++ {
		if a[i - 1] + a[i] >= L {
			tmp = i
		}
	}

	if tmp == 0 {
		fmt.Println("Impossible")
		return
	}

	fmt.Println("Possible")
	for i := 1; i < tmp; i++ {
		fmt.Println(i)
	}

	for i := N - 1; i > tmp; i-- {
		fmt.Println(i)
	}

	fmt.Println(tmp)
}

// Scanner
type scanner struct {
	r	*bufio.Reader
	buf []byte
	p	int
}

func NewScanner() *scanner {
	return &scanner{r: bufio.NewReaderSize(os.Stdin, 10000)}
}

func (s *scanner) next() string {
	s.pre()
	start := s.p

	for ; s.p < len(s.buf); s.p++ {
		if s.buf[s.p] == ' ' {
			break
		}
	}

	result := string(s.buf[start:s.p])
	s.p++
	return result
}

func (s *scanner) Line() string {
	s.pre()
	start := s.p
	s.p = len(s.buf)

	return string(s.buf[start:])
}

func (s *scanner) Int() int {
	v, _ := strconv.Atoi(s.next())
	return v
}

func (s *scanner) Int64() int64 {
	v, _ := strconv.ParseInt(s.next(), 10, 64)
	return v
}

func (s *scanner) Float() float32 {
	f, _ := strconv.ParseFloat(s.next(), 32)

	return float32(f)
}

func (s *scanner) Float64() float64 {
	f, _ := strconv.ParseFloat(s.next(), 64)

	return f
}

func (s *scanner) Bool() bool {
	b, _ := strconv.ParseBool(s.next())

	return b
}

func (s *scanner) String() string {
	return s.next()
}

func (s *scanner) Byte() []byte {
	return []byte(s.String())
}

func (s *scanner) pre() {
	if s.p >= len(s.buf) {
		s.readLine()
		s.p = 0
	}
}

func (s *scanner) readLine() {
	s.buf = make([]byte, 0)
	for {
		l, p, e := s.r.ReadLine()
		if e != nil {
			panic(e)
		}
		s.buf = append(s.buf, l...)
		if !p {
			break
		}
	}
}

// Functions
func Itob(i int) bool {
	if i == 0 {
		return false
	} else {
		return true
	}
}

func Btoi(f bool) int {
	if f {
		return 1
	} else {
		return 0
	}
}

func min(a ...int) int {
	ret := a[0]
	for _, e := range a {
		if e < ret {
			ret = e
		}
	}

	return ret
}

func max(a ...int) int {
	ret := a[0]
	for _, e := range a {
		if e > ret {
			ret = e
		}
	}

	return ret
}

func minInt64(a ...int64) int64 {
	ret := a[0]
	for _, e := range a {
		if e < ret {
			ret = e
		}
	}

	return ret
}

func maxInt64(a ...int64) int64 {
	ret := a[0]
	for _, e := range a {
		if e > ret {
			ret = e
		}
	}

	return ret
}

func minFloat(a ...float32) float32 {
	ret := a[0]
	for _, e := range a {
		if e < ret {
			ret = e
		}
	}

	return ret
}

func maxFloat(a ...float32) float32 {
	ret := a[0]
	for _, e := range a {
		if e > ret {
			ret = e
		}
	}

	return ret
}

func minFloat64(a ...float64) float64 {
	ret := a[0]
	for _, e := range a {
		if e < ret {
			ret = e
		}
	}

	return ret
}

func maxFloat64(a ...float64) float64 {
	ret := a[0]
	for _, e := range a {
		if e > ret {
			ret = e
		}
	}

	return ret
}

func minOther(comp Comparator, a ...interface{}) interface{} {
	ret := a[0]
	for _, e := range a {
		if comp(e, ret) {
			ret = e
		}
	}

	return ret
}

func maxOther(comp Comparator, a ...interface{}) interface{} {
	ret := a[0]
	for _, e := range a {
		if comp(ret, a) {
			ret = e
		}
	}

	return ret
}

func abs(a int) int {
	if a < 0 {
		return -a
	} else {
		return a
	}
}

func absInt64(a int64) int64 {
	if a < 0 {
		return -a
	} else {
		return a
	}
}

func absFloat(a float32) float32 {
	if a < 0 {
		return -a
	} else {
		return a
	}
}

func absFloat64(a float64) float64 {
	if a < 0 {
		return -a
	} else {
		return a
	}
}

func gcd(a, b int) int {
	if b > 0 {
		return gcd(b, a % b)
	} else {
		return a
	}
}

func lcm(a, b int) int {
	return a / gcd(a, b) * b
}

func gcdInt64(a, b int64) int64 {
	if b > 0 {
		return gcdInt64(b, a % b)
	} else {
		return a
	}
}

func lcmInt64(a, b int64) int64 {
	return a / gcdInt64(a, b) * b
}

func ModPow(x, n, mod int) int {
	ret := 1

	for ; n > 0; n /= 2 {
		if (n & 1) == 1 {
			ret = ret * x % mod
		}

		x = x * x % mod
	}

	return ret
}

func ModPowInt64(x, n, mod int64) int64 {
	var ret int64 = 1

	for ; n > 0; n /= 2 {
		if (n & 1) == 1 {
			ret = ret * x % mod
		}

		x = x * x % mod
	}

	return ret
}

func IntComp(a, b interface{}) bool {
	na := a.(int)
	nb := b.(int)

	return na < nb
}

func Int64Comp(a, b interface{}) bool {
	na := a.(int64)
	nb := b.(int64)

	return na < nb
}

func FloatComp(a, b interface{}) bool {
	na := a.(float32)
	nb := b.(float32)

	return na < nb
}

func Float64Comp(a, b interface{}) bool {
	na := a.(float64)
	nb := b.(float64)

	return na < nb
}

// Structs
type Merger func(a, b interface{}) interface{}
type Comparator func(a, b interface{}) bool

// Pair
type Pair struct {
	first, second int64
}

func Newpair() *Pair {
	return &Pair {
		first : 0,
		second : 0,
	}
}

func (p Pair) Less(q Pair) bool {
	if p.first < q.first {
		return true
	} else if p.first == q.first {
		return p.second < q.second
	} else {
		return false
	}
}

func (p Pair) String() string {
	return fmt.Sprint("(", p.first, ", ", p.second, ")")
}

func PairComp(p, q interface{}) bool {
	np := p.(Pair)
	nq := q.(Pair)

	return np.Less(nq)
}

type Pairs []Pair

func (p Pairs) Len() int {
	return len(p)
}

func (p Pairs) Less(i, j int) bool {
	return p[i].Less(p[j])
}

func (p Pairs) Swap(i, j int) {
	p[i], p[j] = p[j], p[i]
}

// Priority Queue
// push : Push the value to the priority queue.
// top  : Return the (Min / Max) value in the priority queue.
// pop  : Delete the (Min / Max) value in the priority queue.
// size : Return the number of values in the priority queue.
// empty : Return Is priority queue has the values.
type PriorityQueue struct {
	data	[]interface{}
	comp	Comparator
}

func NewPriorityQueue(comp Comparator) *PriorityQueue {
	return &PriorityQueue{make([]interface{}, 0), comp}
}

func (qu *PriorityQueue) push(x interface{}) {
	n := len(qu.data)
	qu.data = append(qu.data, x)

	for n != 0 {
		par := (n - 1) / 2

		if qu.comp(qu.data[par], qu.data[n]) {
			qu.data[par], qu.data[n] = qu.data[n], qu.data[par]
		}

		n = par
	}
}

func (qu *PriorityQueue) pop() {
	n := len(qu.data) - 1
	qu.data[0] = qu.data[n]
	qu.data = qu.data[:n]

	for i, j := 0, 1; j < n; {
		j = 2 * i + 1

		if (j != n - 1) && qu.comp(qu.data[j], qu.data[j + 1]) {
			j++
		}

		if qu.comp(qu.data[i], qu.data[j]) {
			qu.data[i], qu.data[j] = qu.data[j], qu.data[i]
		}

		i = j
	}
}

func (qu *PriorityQueue) top() interface{} {
	return qu.data[0]
}

func (qu *PriorityQueue) size() int {
	return len(qu.data)
}

func (qu *PriorityQueue) empty() bool {
	return len(qu.data) == 0
}

// Segment Tree
// update : Update k-th value of SegmentTree.data to x
// get	 : Get the merged value in range [a, b)
type SegmentTree struct {
	data	[]interface{}
	id		interface{}
	size	int
	merge	Merger
}

func NewSegmentTree(n int, id interface{}, merge Merger) *SegmentTree {
	sz := 1
	for sz < n {
		sz *= 2
	}

	data := make([]interface{}, sz * 2  - 1)
	for i := 0; i < sz * 2 - 1; i++ {
		data[i] = id
	}

	return &SegmentTree{data, id, sz, merge}
}

func (seg *SegmentTree) update(k int, x interface{}) {
	k += seg.size - 1;
	seg.data[k] = x

	for k > 0 {
		k = (k - 1) / 2

		seg.data[k] = seg.merge(seg.data[2 * k + 1], seg.data[2 * k + 2])
	}
}

func (seg *SegmentTree) get(a, b int) interface{} {
	return seg._get(a, b, 0, 0, seg.size)
}

func (seg *SegmentTree) _get(a, b, k, l, r int) interface{} {
	if b <= l || r <= a {
		return seg.id
	}

	if a <= l && r <= b {
		return seg.data[k]
	}

	L := seg._get(a, b, 2 * k + 1, l, (l + r) / 2)
	R := seg._get(a, b, 2 * k + 2, (l + r) / 2, r)
	return seg.merge(L, R)
}

func (seg *SegmentTree) String() string {
	return fmt.Sprint(seg.data[seg.size - 1:])
}

// Trie Node
// Node for Trie Tree
const (
	char_size = 26
	margin = 'a'
)

type TrieNode struct {
	nxt 	[char_size]int
	accept	[]int
	exist	int
}

func NewTrieNode() *TrieNode {
	var nxt  [char_size]int
	for i := 0; i < char_size; i++ {
		nxt[i] = -1
	}

	return &TrieNode{nxt, make([]int, 0), 0}
}

// Trie Tree
type TrieTree struct {
	nodes	[]TrieNode
	root	int
}

func NewTrieTree() *TrieTree {
	return &TrieTree{[]TrieNode{*NewTrieNode()}, 0}
}

func direct_action(node, id int) {
	//virtual function
}

func child_action(node, child, id int) {
	//virtual function
}

func (tree *TrieTree) update_direct(node, id int) {
	tree.nodes[node].accept = append(tree.nodes[node].accept, id)
	direct_action(node, id)
}

func (tree *TrieTree) update_child(node, child, id int) {
	tree.nodes[node].exist += 1
	child_action(node, child, id)
}

func (tree *TrieTree) add(str []byte, str_index, node_index, id int) {
	if str_index == len(str) {
		tree.update_direct(node_index, id)
	} else {
		c := int(str[str_index]) - int(margin)

		if tree.nodes[node_index].nxt[c] == -1 {
			tree.nodes[node_index].nxt[c] = len(tree.nodes)
			tree.nodes = append(tree.nodes, *NewTrieNode())
		}

		tree.add(str, str_index + 1, tree.nodes[node_index].nxt[c], id)
		tree.update_child(node_index, tree.nodes[node_index].nxt[c], id)
	}
}

func (tree *TrieTree) InsertWithId(str []byte, id int) {
	tree.add(str, 0, 0, id)
}

func (tree *TrieTree) Insert(str []byte) {
	tree.InsertWithId(str, tree.nodes[0].exist)
}

func (tree *TrieTree) size() int {
	return tree.nodes[0].exist
}

func (tree *TrieTree) nodesize() int {
	return len(tree.nodes)
}


package main

import "fmt"

func main() {
  var a, b, c int

  fmt.Scanf("%d %d %d", &a, &b, &c)
  fmt.Println(a, b, c)

  if a == 7 {
		if b == 5 && c == 5 {
      fmt.Println("YES")
		} else {
			fmt.Println("NO")
		}
	} else if a == 5 {
		if b == 7 && c == 5 {
			fmt.Println("YES")
		} else if b == 5 && c == 7 {
			fmt.Println("YES")
    } else {
      fmt.Println("NO")
    }
  } else {
    fmt.Println("NO")
	}

}

Score : 100 points

Problem Statement

Iroha loves Haiku. Haiku is a short form of Japanese poetry. A Haiku consists of three phrases with 5, 7 and 5 syllables, in this order.

To create a Haiku, Iroha has come up with three different phrases. These phrases have A, B and C syllables, respectively. Determine whether she can construct a Haiku by using each of the phrases once, in some order.

Constraints

1≦A,B,C≦10

Input

The input is given from Standard Input in the following format:

A B C

Output

If it is possible to construct a Haiku by using each of the phrases once, print YES (case-sensitive). Otherwise, print NO.

Sample Input 1

5 5 7

Sample Output 1

YES

Using three phrases of length 5, 5 and 7, it is possible to construct a Haiku.

Sample Input 2

7 7 5

Sample Output 2

NO


package main

import "fmt"

func main() {
    var a, b, c string
    fmt.Scan(&a, &b, &c)

  five := make([]string, 0, 3)
  seven := make([]string, 0, 3)

  for _, s := range []string{a,b,c} {
    if len(s) == 5 {
      five = append(five, s)
    }
    if len(s) == 7 {
      seven = append(seven, s)
    }
  }

  if len(five) == 2 && len(seven) == 1 {
    fmt.Println("YES")
    return
  }
  fmt.Println("NO")
}