package main

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

var rdr = bufio.NewReaderSize(os.Stdin, 1000000)

// readLine can read long line string (at least 10^5)
func readLine() string {
	buf := make([]byte, 0, 1000000)
	for {
		l, p, e := rdr.ReadLine()
		if e != nil {
			panic(e)
		}
		buf = append(buf, l...)
		if !p {
			break
		}
	}
	return string(buf)
}

// NextLine reads a line text from stdin, and then returns its string.
func NextLine() string {
	return readLine()
}

/*
var sc = bufio.NewScanner(os.Stdin)

// NextLine reads a line text from stdin, and then returns its string.
func NextLine() string {
	sc.Scan()
	return sc.Text()
}
*/

// NextIntsLine reads a line text, that consists of **ONLY INTEGERS DELIMITED BY SPACES**, from stdin.
// And then returns intergers slice.
func NextIntsLine() []int {
	ints := []int{}
	intsStr := NextLine()
	tmp := strings.Split(intsStr, " ")
	for _, s := range tmp {
		integer, _ := strconv.Atoi(s)
		ints = append(ints, integer)
	}
	return ints
}

// NextStringsLine reads a line text, that consists of **STRINGS DELIMITED BY SPACES**, from stdin.
// And then returns strings slice.
func NextStringsLine() []string {
	str := NextLine()
	return strings.Split(str, " ")
}

// NextRunesLine reads a line text, that consists of **ONLY CHARACTERS ARRANGED CONTINUOUSLY**, from stdin.
// Ant then returns runes slice.
func NextRunesLine() []rune {
	return []rune(NextLine())
}

// Max returns the max integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Max(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m < integer {
			m = integer
		}
	}
	return m
}

// Min returns the min integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Min(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m > integer {
			m = integer
		}
	}
	return m
}

// PowInt is integer version of math.Pow
func PowInt(a, e int) int {
	if a < 0 || e < 0 {
		panic(errors.New("[argument error]: PowInt does not accept negative integers"))
	}
	fa := float64(a)
	fe := float64(e)
	fanswer := math.Pow(fa, fe)
	return int(fanswer)
}

// AbsInt is integer version of math.Abs
func AbsInt(a int) int {
	fa := float64(a)
	fanswer := math.Abs(fa)
	return int(fanswer)
}

// DeleteElement returns a *NEW* slice, that have the same and minimum length and capacity.
// DeleteElement makes a new slice by using easy slice literal.
func DeleteElement(s []int, i int) []int {
	if i < 0 || len(s) <= i {
		panic(errors.New("[index error]"))
	}
	// appendのみの実装
	n := make([]int, 0, len(s)-1)
	n = append(n, s[:i]...)
	n = append(n, s[i+1:]...)
	return n
}

// Concat returns a *NEW* slice, that have the same and minimum length and capacity.
func Concat(s, t []rune) []rune {
	n := make([]rune, 0, len(s)+len(t))
	n = append(n, s...)
	n = append(n, t...)
	return n
}

// UpperRune is rune version of `strings.ToUpper()`.
func UpperRune(r rune) rune {
	str := strings.ToUpper(string(r))
	return []rune(str)[0]
}

// LowerRune is rune version of `strings.ToLower()`.
func LowerRune(r rune) rune {
	str := strings.ToLower(string(r))
	return []rune(str)[0]
}

// ToggleRune returns a upper case if an input is a lower case, v.v.
func ToggleRune(r rune) rune {
	var str string
	if 'a' <= r && r <= 'z' {
		str = strings.ToUpper(string(r))
	} else if 'A' <= r && r <= 'Z' {
		str = strings.ToLower(string(r))
	} else {
		str = string(r)
	}
	return []rune(str)[0]
}

// ToggleString iteratively calls ToggleRune, and returns the toggled string.
func ToggleString(s string) string {
	inputRunes := []rune(s)
	outputRunes := make([]rune, 0, len(inputRunes))
	for _, r := range inputRunes {
		outputRunes = append(outputRunes, ToggleRune(r))
	}
	return string(outputRunes)
}

// 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
	}
}

// sort package (snippets)
//sort.Sort(sort.IntSlice(s))
//sort.Sort(sort.Reverse(sort.IntSlice(s)))
//sort.Sort(sort.Float64Slice(s))
//sort.Sort(sort.StringSlice(s))

// copy function
//a = []int{0, 1, 2}
//b = make([]int, len(a))
//copy(b, a)

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

var n, a, b int
var X []int

func main() {
	tmp := NextIntsLine()
	n, a, b = tmp[0], tmp[1], tmp[2]
	X = NextIntsLine()
	ans := 0
	for i := 1; i < len(X); i++ {
		before := X[i-1]
		current := X[i]
		dist := current - before
		walkCost := dist * a
		if walkCost > b {
			ans += b
		} else {
			ans += walkCost
		}
	}
	fmt.Println(ans)
}

Score : 500 points

Problem Statement

There are N towns on a line running east-west.
The towns are numbered 1 through N, in order from west to east.
Each point on the line has a one-dimensional coordinate, and a point that is farther east has a greater coordinate value.
The coordinate of town i is X_i.

You are now at town 1, and you want to visit all the other towns.
You have two ways to travel:

Walk on the line.
Your fatigue level increases by A each time you travel a distance of 1, regardless of direction.

Teleport to any location of your choice.
Your fatigue level increases by B, regardless of the distance covered.

Find the minimum possible total increase of your fatigue level when you visit all the towns in these two ways.

Constraints

All input values are integers.

2≤N≤10^5

1≤X_i≤10^9

For all i(1≤i≤N-1), X_i<X_{i+1}.

1≤A≤10^9

1≤B≤10^9

Input

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

N A B
X_1 X_2 ... X_N

Output

Print the minimum possible total increase of your fatigue level when you visit all the towns.

Sample Input 1

4 2 5
1 2 5 7

Sample Output 1

11

From town 1, walk a distance of 1 to town 2, then teleport to town 3, then walk a distance of 2 to town 4.
The total increase of your fatigue level in this case is 2×1+5+2×2=11, which is the minimum possible value.

Sample Input 2

7 1 100
40 43 45 105 108 115 124

Sample Output 2

84

From town 1, walk all the way to town 7.
The total increase of your fatigue level in this case is 84, which is the minimum possible value.

Sample Input 3

7 1 2
24 35 40 68 72 99 103

Sample Output 3

12

Visit all the towns in any order by teleporting six times.
The total increase of your fatigue level in this case is 12, which is the minimum possible value.


package main

import "fmt"

func main() {
	var n, a, b, i int
	fmt.Scan(&n)
	fmt.Scan(&a)
	fmt.Scan(&b)
	x := make([]int, n)
	for i=0; i<n; i++ {
		fmt.Scan(&x[i])
	}
	var result int = 0
	for i=1; i<n; i++ {
		if a * (x[i] - x[i-1]) > b {
			result += b
		} else {
			result += a * (x[i] - x[i-1])
		}
	}
	fmt.Printf("%v\n", result)
}

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

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.


package main

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

var (
	finv, inv, fac [MAX]int
)

func COM(n, k int) int {
	MOD := int(MOD)
	if n < k {
		return 0
	}
	if n < 0 || k < 0 {
		return 0
	}
	return fac[n] * (finv[k] * finv[n-k] % MOD) % MOD
}

func init() {
	MOD := int(MOD)
	fac[0] = 1
	fac[1] = 1
	finv[0] = 1
	finv[1] = 1
	inv[1] = 1
	for i := 2; i < MAX; i++ {
		fac[i] = fac[i-1] * i % MOD
		inv[i] = MOD - inv[MOD%i]*(MOD/i)%MOD
		finv[i] = finv[i-1] * inv[i] % MOD
	}
	//sc.Split(bufio.ScanLines)
	sc.Split(bufio.ScanWords)
	sc.Buffer([]byte{}, 500100)
}

const (
	MAX = 510000
)

var MOD int64 = 1000000007

func ModAdd(a, b int64) int64 {
	return (a + b) % MOD
}

func ModMul(a, b int64) int64 {
	ans := a * b % MOD
	if ans < 0 {
		ans += MOD
	}
	return ans
}

func ModSub(a, b int64) int64 {
	r := (a%MOD - b%MOD) % MOD
	if r < 0 {
		r += MOD
	}
	return r
}

func ModDiv(a, b int64) int64 {
	return a % MOD * ModInv(b) % MOD
}

func ModPow(a, n int64) int64 {
	var r int64 = 1
	for n > 0 {
		if n&1 == 1 {
			r = r * a % MOD
		}
		a = a * a % MOD
		n >>= 1
	}
	return r
}

func ModInv(a int64) int64 {
	var b, u, v int64 = MOD, 1, 0
	for b > 0 {
		t := a / b
		a -= t * b
		a, b = b, a
		u -= t * v
		u, v = v, u
	}
	u %= MOD
	if u < 0 {
		u += MOD
	}
	return u
}

type Q struct {
	value int
	index int
	K     int
}

type QS []*Q

func (p QS) Len() int           { return len(p) }
func (p QS) Less(i, j int) bool { return p[i].value > p[j].value }
func (pq QS) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}

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

func (pq *QS) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	old[n-1] = nil  // avoid memory leak
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

func GCD(a, b int64) int64 {
	if b == 0 {
		return a
	}
	return GCD(b, a%b)
}

func LCM(a, b int64) int64 {
	return a * b / GCD(a, b)
}

type UnionFind struct {
	par  []int
	size []int
}

func NewUnionFind(size int) *UnionFind {
	return new(UnionFind).init(size)
}

func (uf *UnionFind) init(size int) *UnionFind {
	uf.par = make([]int, size)
	uf.size = make([]int, size)

	for i := 0; i < size; i++ {
		uf.par[i] = i
		uf.size[i] = 1
	}
	return uf
}

func (uf *UnionFind) Unite(p int, q int) {
	rp := uf.Root(p)
	rq := uf.Root(q)
	if rp == rq {
		return
	}
	if uf.size[rp] < uf.size[rq] {
		uf.par[rp] = uf.par[rq]
		uf.size[rq] += uf.size[rp]
	} else {
		uf.par[rq] = uf.par[rp]
		uf.size[rp] += uf.size[rq]
	}
}

func (uf *UnionFind) Root(p int) int {
	for uf.par[p] == p {
		return p
	}
	uf.par[p] = uf.Root(uf.par[p])
	return uf.par[p]
}

func (uf *UnionFind) Size(p int) int {
	return uf.size[uf.Root(p)]
}

func (uf *UnionFind) Same(p int, q int) bool {
	return uf.Root(p) == uf.Root(q)
}

var sc = bufio.NewScanner(os.Stdin)

func getInt() int {
	n, _ := strconv.Atoi(getStr())
	return n
}

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

func factor(result map[int]int, num, pnum int) map[int]int {
	if pnum*pnum > num {
		if num != 1 {
			result[num] += 1
		}
		return result
	}

	if num%pnum == 0 {
		num /= pnum
		result[pnum]++
	} else {
		pnum++
	}
	return factor(result, num, pnum)
}

func main() {
	S := strings.ReplaceAll(getStr(), ",", " ")

	fmt.Println(S)
}

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 and Pop use pointer receivers because they modify the slice's length,
	// not just its contents.
	*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 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)
}

Score : 100 points

Problem Statement

As a New Year's gift, Dolphin received a string s of length 19.

The string s has the following format: [five lowercase English letters],[seven lowercase English letters],[five lowercase English letters].

Dolphin wants to convert the comma-separated string s into a space-separated string.

Write a program to perform the conversion for him.

Constraints

The length of s is 19.

The sixth and fourteenth characters in s are ,.

The other characters in s are lowercase English letters.

Input

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

s

Output

Print the string after the conversion.

Sample Input 1

happy,newyear,enjoy

Sample Output 1

happy newyear enjoy

Replace all the commas in happy,newyear,enjoy with spaces to obtain happy newyear enjoy.

Sample Input 2

haiku,atcoder,tasks

Sample Output 2

haiku atcoder tasks

Sample Input 3

abcde,fghihgf,edcba

Sample Output 3

abcde fghihgf edcba


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() {
	sx := getInt() + 2000
	sy := getInt() + 2000
	tx := getInt() + 2000
	ty := getInt() + 2000

	M := make([][]int, 4000)
	for i := 0; i < 4000; i++ {
		M[i] = make([]int, 4000)
	}

	result := proc([]int{sx, sy}, []int{tx, ty}, M)
	result += proc([]int{tx, ty}, []int{sx, sy}, M)
	result += proc([]int{sx, sy}, []int{tx, ty}, M)
	result += proc([]int{tx, ty}, []int{sx, sy}, M)
	fmt.Println(result)
}

func proc(start, end []int, m [][]int) string {
	m[start[1]][start[0]] = 1
	m[end[1]][end[0]] = 0

	pos := []int{start[0], start[1]}
	command := ""
	for ; ; {
		if pos[0] == end[0] && pos[1] == end[1] {
			break
		}

		c := ""

		if pos[0] < end[0] && m[pos[1]][pos[0] + 1] != 1 {
			c = "R"
		} else if pos[0] > end[0] && m[pos[1]][pos[0] - 1] != 1 {
			c = "L"
		} else if pos[1] < end[1] && m[pos[1] + 1][pos[0]] != 1 {
			c = "U"
		} else if pos[1] > end[1] && m[pos[1] - 1][pos[0]] != 1 {
			c = "D"
		} else {
			if pos[0] == end[0] {
				if m[pos[1]][pos[0] + 1] != 1 {
					c = "R"
				} else if m[pos[1]][pos[0] - 1] != 1 {
					c = "L"
				}
			} else {
				if m[pos[1] + 1][pos[0]] != 1 {
					c = "U"
				} else if m[pos[1] - 1][pos[0]] != 1 {
					c = "D"
				}
			}
		}

		command += c
		switch c {
		case "U":
			pos[1]++
			m[pos[1]][pos[0]] = 1
		case "D":
			pos[1]--
			m[pos[1]][pos[0]] = 1
		case "L":
			pos[0]--
			m[pos[1]][pos[0]] = 1
		case "R":
			pos[0]++
			m[pos[1]][pos[0]] = 1
		}
	}

	m[pos[1]][pos[0]] = 0
	return command
}

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 : 300 points

Problem Statement

Dolphin resides in two-dimensional Cartesian plane, with the positive x-axis pointing right and the positive y-axis pointing up.

Currently, he is located at the point (sx,sy). In each second, he can move up, down, left or right by a distance of 1.

Here, both the x- and y-coordinates before and after each movement must be integers.

He will first visit the point (tx,ty) where sx < tx and sy < ty, then go back to the point (sx,sy), then visit the point (tx,ty) again, and lastly go back to the point (sx,sy).

Here, during the whole travel, he is not allowed to pass through the same point more than once, except the points (sx,sy) and (tx,ty).

Under this condition, find a shortest path for him.

Constraints

-1000 ≤ sx < tx ≤ 1000

-1000 ≤ sy < ty ≤ 1000

sx,sy,tx and ty are integers.

Input

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

sx sy tx ty

Output

Print a string S that represents a shortest path for Dolphin.

The i-th character in S should correspond to his i-th movement.

The directions of the movements should be indicated by the following characters:

U: Up

D: Down

L: Left

R: Right

If there exist multiple shortest paths under the condition, print any of them.

Sample Input 1

0 0 1 2

Sample Output 1

UURDDLLUUURRDRDDDLLU

One possible shortest path is:

Going from (sx,sy) to (tx,ty) for the first time: (0,0) → (0,1) → (0,2) → (1,2)

Going from (tx,ty) to (sx,sy) for the first time: (1,2) → (1,1) → (1,0) → (0,0)

Going from (sx,sy) to (tx,ty) for the second time: (0,0) → (-1,0) → (-1,1) → (-1,2) → (-1,3) → (0,3) → (1,3) → (1,2)

Going from (tx,ty) to (sx,sy) for the second time: (1,2) → (2,2) → (2,1) → (2,0) → (2,-1) → (1,-1) → (0,-1) → (0,0)

Sample Input 2

-2 -2 1 1

Sample Output 2

UURRURRDDDLLDLLULUUURRURRDDDLLDL


package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

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

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

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

// Sort
type RuneSlice []rune

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

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	sx, sy, tx, ty := sc.nextInt(), sc.nextInt(), sc.nextInt(), sc.nextInt()
	rev := make(map[rune]string)
	rev['R'] = "L"
	rev['L'] = "R"
	rev['U'] = "D"
	rev['D'] = "U"
	ans := ""
	route := ""
	for i := 0; i < tx-sx; i++ {
		route += "R"
	}
	for i := 0; i < ty-sy; i++ {
		route += "U"
	}
	ans += route
	for i := 0; i < len(route); i++ {
		ans += rev[rune(route[i])]
	}
	route = ""
	route += "D"
	for i := 0; i < tx-sx+1; i++ {
		route += "R"
	}
	for i := 0; i < ty-sy+1; i++ {
		route += "U"
	}
	route += "L"
	ans += route
	for i := 0; i < len(route); i++ {
		ans += rev[rune(route[i])]
	}

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


package main

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

func solve() {
	sx, sy := getInt(), getInt()
	tx, ty := getInt(), getInt()
	dx, dy := tx-sx, ty-sy

	ans := ""
	ans += strings.Repeat("R", dx)
	ans += strings.Repeat("U", dy)
	ans += strings.Repeat("L", dx)
	ans += strings.Repeat("D", dy)

	ans += "D" + strings.Repeat("R", dx+1)
	ans += strings.Repeat("U", dy+1) + "L"
	ans += "U" + strings.Repeat("L", dx+1)
	ans += strings.Repeat("D", dy+1) + "R"

	fmt.Fprintln(wr, ans)
}

// -----------------------------------------

const (
	inf = 1 << 60
	// mod = 1000000007
)

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

func main() {
	// buf := 200001
	// sc.Buffer(make([]byte, buf), buf)
	sc.Split(bufio.ScanWords)
	solve()
	wr.Flush()
}

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

func getIntSlice(n int) []int {
	is := make([]int, n)
	for i := range is {
		is[i] = getInt()
	}
	return is
}

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

func getRunes() []rune {
	return []rune(getString())
}


package main

import "fmt"

type Queue struct {
	q []*point
}

func (q *Queue) Push(i *point) {
	q.q = append(q.q, i)
}

func (q *Queue) Shift() *point {
	top := q.q[0]
	q.q = q.q[1:]
	return top
}

func (q *Queue) Len() int {
	return len(q.q)
}

type Stack struct {
	q []pair
}

func (q *Stack) Push(i pair) {
	q.q = append(q.q, i)
}

func (q *Stack) Pop() pair {
	top := q.q[len(q.q)-1]
	q.q = q.q[:len(q.q)-1]
	return top
}

func (q *Stack) Len() int {
	return len(q.q)
}

var (
	q *Queue
	v [][]bool
	m [][]bool
)

type point struct {
	x    int
	y    int
	prev *point
}

type pair [2]int

func (p pair) X() int {
	return p[0]
}

func (p pair) Y() int {
	return p[1]
}

var vecs = [4]pair{
	{0, 1},
	{1, 0},
	{0, -1},
	{-1, 0},
}

var d = map[pair]string{
	pair{0, 1}:  "U",
	pair{1, 0}:  "R",
	pair{0, -1}: "D",
	pair{-1, 0}: "L",
}

func main() {
	var sx, sy, tx, ty int
	fmt.Scan(&sx, &sy, &tx, &ty)

	q = &Queue{}

	m = make([][]bool, 2001)
	for i := 0; i < 2001; i++ {
		m[i] = make([]bool, 2001)
	}

	start := &point{x: sx + 1000, y: sy + 1000}
	goal := &point{x: tx + 1000, y: ty + 1000}

	for i := 0; i < 4; i++ {
		if i%2 == 0 {
			BFS(start, goal)
		} else {
			BFS(goal, start)
		}
	}
}

func BFS(start, goal *point) {
	v = make([][]bool, 2001)
	for i := 0; i < 2001; i++ {
		v[i] = make([]bool, 2001)
	}
	v[start.x][start.y] = true
	q.Push(start)
	for q.Len() > 0 {
		p := q.Shift()
		if p.x == goal.x && p.y == goal.y {
			s := &Stack{}
			for p.prev != nil {
				m[p.x][p.y] = true
				s.Push(pair{p.x - p.prev.x, p.y - p.prev.y})
				p = p.prev
			}
			for s.Len() > 0 {
				fmt.Println(d[s.Pop()])
			}
			return
		}
		for i := 0; i < 4; i++ {
			x := p.x + vecs[i].X()
			y := p.y + vecs[i].Y()
			if !v[x][y] && !m[x][y] {
				v[x][y] = true
				q.Push(&point{x: x, y: y, prev: p})
			}
		}
	}
}


package main

import (
	"fmt"
)

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

	if op == "+" {
		fmt.Println(a+b)
	} else {
		fmt.Println(a-b)
	}
}

Score : 100 points

Problem Statement

Joisino wants to evaluate the formula "A op B".
Here, A and B are integers, and the binary operator op is either + or -.
Your task is to evaluate the formula instead of her.

Constraints

1≦A,B≦10^9

op is either + or -.

Input

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

A op B

Output

Evaluate the formula and print the result.

Sample Input 1

1 + 2

Sample Output 1

3

Since 1 + 2 = 3, the output should be 3.

Sample Input 2

5 - 7

Sample Output 2

-2


package main

import "fmt"

func check(b byte) string {
	switch b {
	case 'a', 'e', 'i', 'o', 'u':
		return "vowel"
	}
	return "consonant"
}

func main() {
	var s string
	fmt.Scan(&s)
	fmt.Println(check(s[0]))
}

Score : 100 points

Problem Statement

Given a lowercase English letter c, determine whether it is a vowel. Here, there are five vowels in the English alphabet: a, e, i, o and u.

Constraints

c is a lowercase English letter.

Input

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

c

Output

If c is a vowel, print vowel. Otherwise, print consonant.

Sample Input 1

a

Sample Output 1

vowel

Since a is a vowel, print vowel.

Sample Input 2

z

Sample Output 2

consonant

Sample Input 3

s

Sample Output 3

consonant


package main

import "fmt"

func main() {
	var h, w int
	fmt.Scan(&h, &w)
	var c string
	for i := 0; i < h; i++ {
		fmt.Scan(&c)
		fmt.Println(c)
		fmt.Println(c)
	}
}


package main

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

const scBufSize = 1 * 1024 * 1024 // 1MB
var sc = func() *bufio.Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Buffer(make([]byte, scBufSize), scBufSize)
	sc.Split(bufio.ScanWords)
	return sc
}()

func main() {
	n := scani()
	k := scani()
	l := scani()

	road := con(n, k)
	rail := con(n, l)

	for i := 0; i < n; i++ {
		c := 0
		for j := 0; j < n; j++ {
			if road[i][j] && rail[i][j] {
				c++
			}
		}
		os.Stdout.WriteString(strconv.Itoa(c))
	}
}

func con(n, k int) [][]bool {
	road := getmap(n)
	for i := 0; i < k; i++ {
		o, d := scanRoad()
		road[o][d] = true
		road[d][o] = true
	}
	s1 := 0
	for {
		connect(n, road)
		new := sum(road)
		if s1 == new {
			break
		}
		s1 = new
	}
	return road
}

func getmap(n int) [][]bool {
	r := make([][]bool, n)
	for i := 0; i < n; i++ {
		s := make([]bool, n)
		s[i] = true
		r[i] = s
	}
	return r
}

func connect(n int, r [][]bool) [][]bool {
	ret := getmap(n)
	for i, a := range r {
		for j, b := range a {
			if b {
				ret[i] = add(r[i], r[j])
			}
		}
	}
	return ret
}

func add(a, b []bool) []bool {
	for i := range a {
		a[i] = a[i] || b[i]
	}
	return a
}

func sum(r [][]bool) int {
	s := 0
	for i := 0; i < len(r); i++ {
		for _, b := range r[i] {
			if b {
				s++
			}
		}
	}
	return s
}
func scani() int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return i
}
func scanRoad() (o, d int) {
	o = scani() - 1
	d = scani() - 1
	return
}

Score : 400 points

Problem Statement

There are N cities. There are also K roads and L railways, extending between the cities.
The i-th road bidirectionally connects the p_i-th and q_i-th cities, and the i-th railway bidirectionally connects the r_i-th and s_i-th cities.
No two roads connect the same pair of cities. Similarly, no two railways connect the same pair of cities.

We will say city A and B are connected by roads if city B is reachable from city A by traversing some number of roads. Here, any city is considered to be connected to itself by roads.
We will also define connectivity by railways similarly.

For each city, find the number of the cities connected to that city by both roads and railways.

Constraints

2 ≦ N ≦ 2*10^5

1 ≦ K, L≦ 10^5

1 ≦ p_i, q_i, r_i, s_i ≦ N

p_i < q_i

r_i < s_i

When i ≠ j, (p_i, q_i) ≠ (p_j, q_j)

When i ≠ j, (r_i, s_i) ≠ (r_j, s_j)

Input

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

N K L
p_1 q_1
:
p_K q_K
r_1 s_1
:
r_L s_L

Output

Print N integers. The i-th of them should represent the number of the cities connected to the i-th city by both roads and railways.

Sample Input 1

4 3 1
1 2
2 3
3 4
2 3

Sample Output 1

1 2 2 1

All the four cities are connected to each other by roads.

By railways, only the second and third cities are connected. Thus, the answers for the cities are 1, 2, 2 and 1, respectively.

Sample Input 2

4 2 2
1 2
2 3
1 4
2 3

Sample Output 2

1 2 2 1

Sample Input 3

7 4 4
1 2
2 3
2 5
6 7
3 5
4 5
3 4
6 7

Sample Output 3

1 1 2 1 2 2 2


package main

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

func main() {
  input := Input{bufio.NewReaderSize(os.Stdin,100)}
  n,a,b := input.Next3Ints()
  a,b = a-1,b-1
  x := make([]int,n)
  y := make([]int,n)
  p := make(Pairs,n)
  q := make(Pairs,n)
  for i:=0;i<n;i++ {
    xi,yi := input.Next2Ints()
    x[i] = xi+yi
    y[i] = xi-yi
    p[i] = Pair{x[i],y[i],i}
    q[i] = Pair{y[i],x[i],i}
  }
  d := max(abs(x[b]-x[a]),abs(y[b]-y[a]))
  sort.Sort(p)
  sort.Sort(q)
  s := make(map[int]struct{})
  var dfs func(int)
  dfs = func(u int) {
    s[u] = struct{}{}
    tmp11 := Pair{x[u]-d,y[u]-d-1,-1}
    tmp12 := Pair{x[u]-d,y[u]+d+1,-1}
    tmp21 := Pair{x[u]+d,y[u]-d-1,-1}
    tmp22 := Pair{x[u]+d,y[u]+d+1,-1}
    tmp31 := Pair{y[u]-d,x[u]-d-1,-1}
    tmp32 := Pair{y[u]-d,x[u]+d+1,-1}
    tmp41 := Pair{y[u]+d,x[u]-d-1,-1}
    tmp42 := Pair{y[u]+d,x[u]+d+1,-1}
    l1 := sort.Search(n,func(i int) bool { return tmp11.Less(p[i]) })
    u1 := sort.Search(n,func(i int) bool { return tmp12.Less(p[i]) })
    l2 := sort.Search(n,func(i int) bool { return tmp21.Less(p[i]) })
    u2 := sort.Search(n,func(i int) bool { return tmp22.Less(p[i]) })
    l3 := sort.Search(n,func(i int) bool { return tmp31.Less(q[i]) })
    u3 := sort.Search(n,func(i int) bool { return tmp32.Less(q[i]) })
    l4 := sort.Search(n,func(i int) bool { return tmp41.Less(q[i]) })
    u4 := sort.Search(n,func(i int) bool { return tmp42.Less(q[i]) })
    for i:=l1;i<u1;i++ {
      if _,ok := s[p[i].i];!ok { dfs(p[i].i) }
    }
    for i:=l2;i<u2;i++ {
      if _,ok := s[p[i].i];!ok { dfs(p[i].i) }
    }
    for i:=l3;i<u3;i++ {
      if _,ok := s[q[i].i];!ok { dfs(q[i].i) }
    }
    for i:=l4;i<u4;i++ {
      if _,ok := s[q[i].i];!ok { dfs(q[i].i) }
    }
  }
  dfs(a)
  fmt.Println(len(s))
}

func max(x,y int) int {
  if x > y { return x }
  return y
}
func abs(x int) int {
  if x < 0 { return -x }
  return x
}

type Pair struct { f,s,i int }
func(p Pair) Less(q Pair) bool {
  if p.f == q.f { return p.s < q.s }
  return p.f < q.f
}
type Pairs []Pair
func(p Pairs) Len() int { return len(p) }
func(p Pairs) Swap(i,j int) { p[i],p[j] = p[j],p[i] }
func(p Pairs) Less(i,j int) bool { return p[i].Less(p[j]) }

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) Next2Ints() (int,int) {
  s := strings.Fields(i.NextLine())
  x,_ := strconv.Atoi(s[0])
  y,_ := strconv.Atoi(s[1])
  return x,y
}
func(i *Input) Next3Ints() (int,int,int) {
  s := strings.Fields(i.NextLine())
  x,_ := strconv.Atoi(s[0])
  y,_ := strconv.Atoi(s[1])
  z,_ := strconv.Atoi(s[2])
  return x,y,z
}

Score : 900 points

Problem Statement

There are N pinholes on the xy-plane. The i-th pinhole is located at (x_i,y_i).

We will denote the Manhattan distance between the i-th and j-th pinholes as d(i,j)(=|x_i-x_j|+|y_i-y_j|).

You have a peculiar pair of compasses, called Manhattan Compass.
This instrument always points at two of the pinholes.
The two legs of the compass are indistinguishable, thus we do not distinguish the following two states: the state where the compass points at the p-th and q-th pinholes, and the state where it points at the q-th and p-th pinholes.

When the compass points at the p-th and q-th pinholes and d(p,q)=d(p,r), one of the legs can be moved so that the compass will point at the p-th and r-th pinholes.

Initially, the compass points at the a-th and b-th pinholes.
Find the number of the pairs of pinholes that can be pointed by the compass.

Constraints

2≦N≦10^5

1≦x_i, y_i≦10^9

1≦a < b≦N

When i ≠ j, (x_i, y_i) ≠ (x_j, y_j)

x_i and y_i are integers.

Input

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

N a b
x_1 y_1
:
x_N y_N

Output

Print the number of the pairs of pinholes that can be pointed by the compass.

Sample Input 1

5 1 2
1 1
4 3
6 1
5 5
4 8

Sample Output 1

4

Initially, the compass points at the first and second pinholes.

Since d(1,2) = d(1,3), the compass can be moved so that it will point at the first and third pinholes.

Since d(1,3) = d(3,4), the compass can also point at the third and fourth pinholes.

Since d(1,2) = d(2,5), the compass can also point at the second and fifth pinholes.

No other pairs of pinholes can be pointed by the compass, thus the answer is 4.

Sample Input 2

6 2 3
1 3
5 3
3 5
8 4
4 7
2 5

Sample Output 2

4

Sample Input 3

8 1 2
1 5
4 3
8 2
4 7
8 8
3 3
6 6
4 8

Sample Output 3

7


package main

import "fmt"

func main() {
	var a, b, x int
	fmt.Scan(&a, &b, &x)
	fmt.Println(b/x - (a-1)/x)
}

Score : 200 points

Problem Statement

You are given nonnegative integers a and b (a ≤ b), and a positive integer x.
Among the integers between a and b, inclusive, how many are divisible by x?

Constraints

0 ≤ a ≤ b ≤ 10^{18}

1 ≤ x ≤ 10^{18}

Input

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

a b x

Output

Print the number of the integers between a and b, inclusive, that are divisible by x.

Sample Input 1

4 8 2

Sample Output 1

3

There are three integers between 4 and 8, inclusive, that are divisible by 2: 4, 6 and 8.

Sample Input 2

0 5 1

Sample Output 2

6

There are six integers between 0 and 5, inclusive, that are divisible by 1: 0, 1, 2, 3, 4 and 5.

Sample Input 3

9 9 2

Sample Output 3

0

There are no integer between 9 and 9, inclusive, that is divisible by 2.

Sample Input 4

1 1000000000000000000 3

Sample Output 4

333333333333333333

Watch out for integer overflows.


package main

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

type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buffer []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buffer = append(buffer, line...)
		if !isPrefix {
			break
		}
	}
	return string(buffer)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	r := io.tokens[io.nextToken]
	io.nextToken++
	return r
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextLong() int64 {
	i, err := strconv.ParseInt(io.Next(), 10, 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextDouble() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) PrintLn(a ...interface{}) {
	for i, v := range a {
		if i > 0 {
			io.writer.WriteByte(' ')
		}
		fmt.Fprint(io.writer, v)
	}
	io.writer.WriteByte('\n')
}

func (io *Io) PrintfLn(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format + "\n", a...)
}

func (io *Io) PrintIntLn(a ...int) {
	for i, v := range a {
		if i > 0 {
			io.writer.WriteByte(' ')
		}
		fmt.Fprint(io.writer, v)
	}
	io.writer.WriteByte('\n')
}

func (io *Io) PrintStringLn(a ...string) {
	for i, v := range a {
		if i > 0 {
			io.writer.WriteByte(' ')
		}
		fmt.Fprint(io.writer, v)
	}
	io.writer.WriteByte('\n')
}

type Tuple2 struct {
	first, second int
}

func main() {
	io := NewIo()
	defer io.Flush()
	a, b, x := io.NextLong(), io.NextLong(), io.NextLong()
	divA := (a - 1) / x
	divB := b / x
	if a == 0 {
		fmt.Println(divB + 1)
	} else {
		fmt.Println(divB - divA)
	}
}


package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

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

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

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

// Sort
type RuneSlice []rune

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

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N, x := sc.nextInt(), sc.nextInt()
	A := sc.nextIntSlice(N)
	ans := 0
	for i := 1; i < N; i++ {
		sum := A[i] + A[i-1]
		if sum > x {
			A[i] = max(A[i]-sum+x, 0)
			ans += sum - x
		}
	}

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

Score : 300 points

Problem Statement

There are N boxes arranged in a row.
Initially, the i-th box from the left contains a_i candies.

Snuke can perform the following operation any number of times:

Choose a box containing at least one candy, and eat one of the candies in the chosen box.

His objective is as follows:

Any two neighboring boxes contain at most x candies in total.

Find the minimum number of operations required to achieve the objective.

Constraints

2 ≤ N ≤ 10^5

0 ≤ a_i ≤ 10^9

0 ≤ x ≤ 10^9

Input

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

N x
a_1 a_2 ... a_N

Output

Print the minimum number of operations required to achieve the objective.

Sample Input 1

3 3
2 2 2

Sample Output 1

1

Eat one candy in the second box.
Then, the number of candies in each box becomes (2, 1, 2).

Sample Input 2

6 1
1 6 1 2 0 4

Sample Output 2

11

For example, eat six candies in the second box, two in the fourth box, and three in the sixth box.
Then, the number of candies in each box becomes (1, 0, 1, 0, 0, 1).

Sample Input 3

5 9
3 1 4 1 5

Sample Output 3

0

The objective is already achieved without performing operations.

Sample Input 4

2 0
5 5

Sample Output 4

10

All the candies need to be eaten.


package main

import (
	"math/rand"
	"time"
	"os"
	"bufio"
	"fmt"
	"strconv"
	"strings"
)

var(
	inf = 10000000071000000
	sc = bufio.NewScanner(os.Stdin)
	stdin = bufio.NewReader(os.Stdin)
	mod = 1000000007
	mod9 = 1000000009
)

func init()  {
	rand.Seed(time.Now().UnixNano())
	buf := make([]byte, 0) //ここのサイズは何でもよさそう
	sc.Buffer(buf, 1000000009)
}

func main() {
	n := goint();m := goint()
	uni := &UnionFind{}
	uni.uniInit(n+m)
	for i:=0;i<n;i++{
		k := goint()
		for j:=0;j<k;j++{
			l := goint()
			uni.connect(i,l+n-1)
		}
	}
	num := uni.size(0)
	c := 0
	for i:=n;i<n+m;i++{
		if uni.root(0) != uni.root(i){
			c ++
		}
	}
	if num - (m - c) == n{
		fmt.Println("YES")
	} else {
		fmt.Println("NO")
	}
}

//Union-Find
type UnionFind struct {
	par []int
}

func (u *UnionFind) uniInit(n int)  {
	u.par = make([]int,n)
	for i:=0;i<n;i++{
		u.par[i] = -1
	}
}

//aがどのグループに属しているか
func (u *UnionFind) root (a int) int {
	if u.par[a] < 0{
		return a
	}
	u.par[a] = u.root(u.par[a])
	return u.par[a]
}

//自分のグループの頂点数
func (u *UnionFind) size (a int) int {
	return -u.par[u.root(a)]
}

//つなげる
func (u *UnionFind) connect(a,b int) bool {
	a = u.root(a)
	b = u.root(b)
	if a == b {
		return false
	}
	if u.size(a) < u.size(b) {a,b = b,a}
	u.par[a] += u.par[b]
	u.par[b] = a
	return true
}

//||||||||||||||||||||||||||入力|||||||||||||||||||||||||||||||||||||||\
//数字一文字入力
func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

//文字列を一行入力
func nextLine() string {
	sc.Scan()
	return sc.Text()
}

//空白区切りの文字列の入力
func spaceLine() []string {
	sc.Scan()
	return strings.Split(sc.Text()," ")
}

//数字を一行入力
func intLine() []int {
	str := spaceLine()
	buf := make([]int,len(str))
	for i,s:=range str{
		buf[i],_ = strconv.Atoi(s)
	}
	return buf
}

//次のスペースか改行まで読み込む
func gostring() string {
	byte_ls := make([]byte,0)
	for  {
		b, _ := stdin.ReadByte()
		if b == 32 || b == 10 || b == 0{
			return string(byte_ls)
		} else if b == 13 {
			continue
		} else {
			byte_ls = append(byte_ls,b)
		}
	}
}

//上の関数のintバージョン
func goint() int {
	n,_ := strconv.Atoi(gostring())
	return n
}

//|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

func sum(a ...int) int {
	ans := 0
	for i:=0;i<len(a);i++{
		ans += a[i]
	}
	return ans
}

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

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

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

Score : 400 points

Problem Statement

On a planet far, far away, M languages are spoken. They are conveniently numbered 1 through M.

For CODE FESTIVAL 20XX held on this planet, N participants gathered from all over the planet.

The i-th (1≦i≦N) participant can speak K_i languages numbered L_{i,1}, L_{i,2}, ..., L_{i,{}K_i}.

Two participants A and B can communicate with each other if and only if one of the following conditions is satisfied:

There exists a language that both A and B can speak.

There exists a participant X that both A and B can communicate with.

Determine whether all N participants can communicate with all other participants.

Constraints

2≦N≦10^5

1≦M≦10^5

1≦K_i≦M

(The sum of all K_i)≦10^5

1≦L_{i,j}≦M

L_{i,1}, L_{i,2}, ..., L_{i,{}K_i} are pairwise distinct.

Partial Score

200 points will be awarded for passing the test set satisfying the following: N≦1000, M≦1000 and (The sum of all K_i)≦1000.

Additional 200 points will be awarded for passing the test set without additional constraints.

Input

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

N M
K_1 L_{1,1} L_{1,2} ... L_{1,{}K_1}
K_2 L_{2,1} L_{2,2} ... L_{2,{}K_2}
:
K_N L_{N,1} L_{N,2} ... L_{N,{}K_N}

Output

If all N participants can communicate with all other participants, print YES. Otherwise, print NO.

Sample Input 1

4 6
3 1 2 3
2 4 2
2 4 6
1 6

Sample Output 1

YES

Any two participants can communicate with each other, as follows:

Participants 1 and 2: both can speak language 2.

Participants 2 and 3: both can speak language 4.

Participants 1 and 3: both can communicate with participant 2.

Participants 3 and 4: both can speak language 6.

Participants 2 and 4: both can communicate with participant 3.

Participants 1 and 4: both can communicate with participant 2.

Note that there can be languages spoken by no participant.

Sample Input 2

4 4
2 1 2
2 1 2
1 3
2 4 3

Sample Output 2

NO

For example, participants 1 and 3 cannot communicate with each other.


package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strings"
)

func main() {
	if false {
		test()
	} else {
		solve(bufio.NewReader(os.Stdin), os.Stdout)
	}
}

func solve(r io.Reader, w io.Writer) {
	var n int // number of participants
	var m int // number of languages
	fmt.Fscanln(r, &n, &m)

	g := make(map[int][]int)

	for i := 0; i < n; i++ {
		var langs int
		fmt.Fscan(r, &langs)
		g[i] = make([]int, 0, langs)
		for j := 0; j < langs; j++ {
			var lang int
			fmt.Fscan(r, &lang)
			langi := n + lang - 1
			g[i] = append(g[i], langi)
			g[langi] = append(g[langi], i)
		}
	}

	seen := make([]bool, n+m)
	q := []int{0}
	for len(q) > 0 {
		v := q[0]
		q = q[1:]
		if !seen[v] {
			seen[v] = true
			q = append(q, g[v]...)
		}
	}

	for i := 0; i < n; i++ {
		if !seen[i] {
			fmt.Fprintln(w, "NO")
			return
		}
	}
	fmt.Fprintln(w, "YES")
	return
}

func test() {
	tests := []struct {
		in   string
		want string
	}{
		{
			in: `4 6
3 1 2 3
2 4 2
2 4 6
1 6`,
			want: `YES
`,
		},
		{
			in: `4 4
2 1 2
2 1 2
1 3
2 4 3`,
			want: `NO
`,
		},
	}
	for i, tt := range tests {
		fmt.Printf("=== TEST %d\n", i)
		buf := new(bytes.Buffer)
		solve(strings.NewReader(tt.in), buf)
		if got := buf.String(); got != tt.want {
			fmt.Printf("%d: got %v, want %v\n", i, got, tt.want)
		}
	}
}


package main

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

func main() {
	sc := NewScanner()
	N, M := sc.NextInt(), sc.NextInt()
	list := make([][]int, M)
	has := make([][]int, N)

	for i := 0; i < M; i++ {
		list[i] = make([]int, 0)
	}
	for i := 0; i < N; i++ {
		K := sc.NextInt()
		has[i] = make([]int, K)

		for j := 0; j < K; j++ {
			k := sc.NextInt() - 1
			list[k] = append(list[k], i)
			has[i][j] = k
		}
	}

	start := 0
	check := make([]bool, N)
	queue := make([]int, N)
	check[start] = true
	queue[0] = start
	last := 1
	for p := 0; p < last; p++ {
		current := queue[p]
		for _, k := range has[current] {
			for _, nx := range list[k] {
				if check[nx] {
					continue
				}

				println(last, nx)

				queue[last] = nx
				last++
				check[nx] = true
				break
			}

		}
	}
	if last == N {
		fmt.Println("YES")
	} else {
		fmt.Println("NO")
	}
}

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
		}
	}
}


package main

import (
	"bufio"
	"fmt"
	"math"
	"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 pow64(x, y int64) int64 {
	return int64(math.Pow(float64(x), float64(y)))
}

func pow(x, y int) int {
	return int(pow64(int64(x), int64(y)))
}

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

type queue struct {
	data [][]int
	from int
	to   int
}

func (q *queue) push(d []int) {
	q.data[q.to] = d
	q.to++
}

func (q *queue) pop() []int {
	d := q.data[q.from]
	q.from++
	return d
}

var dh = []int{0, 1}
var dw = []int{1, 0}

func solve() {
	H, W := nextInt(), nextInt()
	A := make([]string, H)
	for i := 0; i < H; i++ {
		A[i] = nextLine()
	}

	q := queue{make([][]int, H*W), 0, 0}

	if A[0][0] == '#' {
		q.push([]int{0, 0})
	}

	n := 0
	for i := 0; i < H; i++ {
		for j := 0; j < W; j++ {
			if A[i][j] == '#' {
				n++
			}
		}
	}

	reached := false

	for q.from != q.to {
		d := q.pop()
		n--
		if d[0] == H-1 && d[1] == W-1 {
			reached = true
			break
		}
		for i := 0; i < 2; i++ {
			nh := d[0] + dh[i]
			nw := d[1] + dw[i]
			if nh >= H || nw >= W {
				continue
			}
			if A[nh][nw] == '.' {
				continue
			}
			q.push([]int{nh, nw, d[0], d[1]})
		}
	}

	if n == 0 && reached {
		out("Possible")
	} else {
		out("Impossible")
	}
}

Score : 200 points

Problem Statement

#nck {
width: 30px;
height: auto;
}

We have a grid of H rows and W columns. Initially, there is a stone in the top left cell. Shik is trying to move the stone to the bottom right cell. In each step, he can move the stone one cell to its left, up, right, or down (if such cell exists). It is possible that the stone visits a cell multiple times (including the bottom right and the top left cell).

You are given a matrix of characters a_{ij} (1 \leq i \leq H, 1 \leq j \leq W). After Shik completes all moving actions, a_{ij} is # if the stone had ever located at the i-th row and the j-th column during the process of moving. Otherwise, a_{ij} is .. Please determine whether it is possible that Shik only uses right and down moves in all steps.

Constraints

2 \leq H, W \leq 8

a_{i,j} is either # or ..

There exists a valid sequence of moves for Shik to generate the map a.

Input

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

H W
a_{11}a_{12}...a_{1W}
:
a_{H1}a_{H2}...a_{HW}

Output

If it is possible that Shik only uses right and down moves, print Possible. Otherwise, print Impossible.

Sample Input 1

4 5
##...
.##..
..##.
...##

Sample Output 1

Possible

The matrix can be generated by a 7-move sequence: right, down, right, down, right, down, and right.

Sample Input 2

5 3
###
..#
###
#..
###

Sample Output 2

Impossible

Sample Input 3

4 5
##...
.###.
.###.
...##

Sample Output 3

Impossible


package main

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

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

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

func init() {
	ReadString = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	// Split sets the split function for the Scanner. The default split function is ScanLines.
	// Split panics if it is called after scanning has started.
	r.Split(bufio.ScanWords)

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

// ReadInt returns an integer.
func ReadInt() int {
	return int(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
}

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

/*********** Arithmetic ***********/

// Max returns the max integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Max(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m < integer {
			m = integer
		}
	}
	return m
}

// Min returns the min integer among input set.
// This function needs at least 1 argument (no argument causes panic).
func Min(integers ...int) int {
	m := integers[0]
	for i, integer := range integers {
		if i == 0 {
			continue
		}
		if m > integer {
			m = integer
		}
	}
	return m
}

// PowInt is integer version of math.Pow
// PowInt calculate a power by Binary Power (二分累乗法(O(log e))).
func PowInt(a, e int) int {
	if a < 0 || e < 0 {
		panic(errors.New("[argument error]: PowInt does not accept negative integers"))
	}

	if e == 0 {
		return 1
	}

	if e%2 == 0 {
		halfE := e / 2
		half := PowInt(a, halfE)
		return half * half
	}

	return a * PowInt(a, e-1)
}

// AbsInt is integer version of math.Abs
func AbsInt(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

// Gcd returns the Greatest Common Divisor of two natural numbers.
// Gcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Gcd uses the Euclidean Algorithm.
func Gcd(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}
	if a < b {
		a, b = b, a
	}

	// Euclidean Algorithm
	for b > 0 {
		div := a % b
		a, b = b, div
	}

	return a
}

// Lcm returns the Least Common Multiple of two natural numbers.
// Lcd only accepts two natural numbers (a, b >= 1).
// 0 or negative number causes panic.
// Lcd uses the Euclidean Algorithm indirectly.
func Lcm(a, b int) int {
	if a <= 0 || b <= 0 {
		panic(errors.New("[argument error]: Gcd only accepts two NATURAL numbers"))
	}

	// a = a'*gcd, b = b'*gcd, a*b = a'*b'*gcd^2
	// a' and b' are relatively prime numbers
	// gcd consists of prime numbers, that are included in a and b
	gcd := Gcd(a, b)

	// not (a * b / gcd), because of reducing a probability of overflow
	return (a / gcd) * b
}

/*********** Utilities ***********/

// DeleteElement returns a *NEW* slice, that have the same and minimum length and capacity.
// DeleteElement makes a new slice by using easy slice literal.
func DeleteElement(s []int, i int) []int {
	if i < 0 || len(s) <= i {
		panic(errors.New("[index error]"))
	}
	// appendのみの実装
	n := make([]int, 0, len(s)-1)
	n = append(n, s[:i]...)
	n = append(n, s[i+1:]...)
	return n
}

// Concat returns a *NEW* slice, that have the same and minimum length and capacity.
func Concat(s, t []rune) []rune {
	n := make([]rune, 0, len(s)+len(t))
	n = append(n, s...)
	n = append(n, t...)
	return n
}

// UpperRune is rune version of `strings.ToUpper()`.
func UpperRune(r rune) rune {
	str := strings.ToUpper(string(r))
	return []rune(str)[0]
}

// LowerRune is rune version of `strings.ToLower()`.
func LowerRune(r rune) rune {
	str := strings.ToLower(string(r))
	return []rune(str)[0]
}

// ToggleRune returns a upper case if an input is a lower case, v.v.
func ToggleRune(r rune) rune {
	var str string
	if 'a' <= r && r <= 'z' {
		str = strings.ToUpper(string(r))
	} else if 'A' <= r && r <= 'Z' {
		str = strings.ToLower(string(r))
	} else {
		str = string(r)
	}
	return []rune(str)[0]
}

// ToggleString iteratively calls ToggleRune, and returns the toggled string.
func ToggleString(s string) string {
	inputRunes := []rune(s)
	outputRunes := make([]rune, 0, len(inputRunes))
	for _, r := range inputRunes {
		outputRunes = append(outputRunes, ToggleRune(r))
	}
	return string(outputRunes)
}

// 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
	}
}

/*********** Permutation ***********/

// memo: 10! == 3628800 > 3M
func CalcFactorialPatterns(elements []rune) [][]rune {
	copiedResidual := make([]rune, len(elements))
	copy(copiedResidual, elements)
	return factorialRecursion([]rune{}, copiedResidual)
}
func factorialRecursion(interim, residual []rune) [][]rune {
	if len(residual) == 0 {
		return [][]rune{interim}
	}

	res := [][]rune{}
	for idx, elem := range residual {
		copiedInterim := make([]rune, len(interim))
		copy(copiedInterim, interim)
		copiedInterim = append(copiedInterim, elem)
		copiedResidual := genDeletedSlice(idx, residual)
		res = append(res, factorialRecursion(copiedInterim, copiedResidual)...)
	}

	return res
}
func genDeletedSlice(delId int, S []rune) []rune {
	res := []rune{}
	res = append(res, S[:delId]...)
	res = append(res, S[delId+1:]...)
	return res
}

// memo: 3**10 == 59049
func CalcDuplicatePatterns(elements []rune, digit int) [][]rune {
	return duplicateRecursion([]rune{}, elements, digit)
}
func duplicateRecursion(interim, elements []rune, digit int) [][]rune {
	if len(interim) == digit {
		return [][]rune{interim}
	}

	res := [][]rune{}
	for i := 0; i < len(elements); i++ {
		copiedInterim := make([]rune, len(interim))
		copy(copiedInterim, interim)
		copiedInterim = append(copiedInterim, elements[i])
		res = append(res, duplicateRecursion(copiedInterim, elements, digit)...)
	}

	return res
}

// usage
//tmp := CalcFactorialPatterns([]rune{'a', 'b', 'c'})
//expected := []string{"abc", "acb", "bac", "bca", "cab", "cba"}
//tmp := CalcDuplicatePatterns([]rune{'a', 'b', 'c'}, 3)
//expected := []string{"aaa", "aab", "aac", "aba", "abb", "abc", ...}

/*********** Binary Search ***********/

// LowerBound returns an index of a slice whose value(s[idx]) is EQUAL TO AND LARGER THAN A KEY.
// The idx is the most left one when there are many keys.
// In other words, the idx is the point where the argument key should be inserted.
func LowerBound(s []int, key int) int {
	isLargerAndEqual := func(index, key int) bool {
		if s[index] >= key {
			return true
		}
		return false
	}

	left, right := -1, len(s)

	for right-left > 1 {
		mid := left + (right-left)/2
		if isLargerAndEqual(mid, key) {
			right = mid
		} else {
			left = mid
		}
	}

	return right
}

// UpperBound returns an index of a slice whose value(s[idx]) is LARGER THAN A KEY.
// The idx is the most right one when there are many keys.
// In other words, the idx is the point where the argument key should be inserted.
func UpperBound(s []int, key int) int {
	isLarger := func(index, key int) bool {
		if s[index] > key {
			return true
		}
		return false
	}

	left, right := -1, len(s)

	for right-left > 1 {
		mid := left + (right-left)/2
		if isLarger(mid, key) {
			right = mid
		} else {
			left = mid
		}
	}

	return right
}

// usage
//test := []int{1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 10, 10, 10, 20, 20, 20, 30, 30, 30}
//assert.Equal(t, 5, UpperBound(test, 5)-LowerBound(test, 5))
//assert.Equal(t, 0, UpperBound(test, 15)-LowerBound(test, 15))

/*********** Union Find ***********/

func InitParents(parents []int, maxNodeId int) {
	for i := 0; i <= maxNodeId; i++ {
		parents[i] = i
	}
}

func unite(x, y int, parents []int) {
	xp, yp := root(x, parents), root(y, parents)
	if xp == yp {
		return
	}

	parents[xp] = yp
}

func same(x, y int, parents []int) bool {
	return root(x, parents) == root(y, parents)
}

func root(x int, parents []int) int {
	if parents[x] == x {
		return x
	}

	parents[x] = root(parents[x], parents)
	return parents[x]
}

/*********** Factorization, Prime Number ***********/

// TrialDivision returns the result of prime factorization of integer N.
// Complicity: O(n)
func TrialDivision(n int) map[int]int {
	if n <= 1 {
		panic(errors.New("[argument error]: TrialDivision only accepts a NATURAL number"))
	}

	p := map[int]int{}
	for i := 2; i*i <= n; i++ {
		exp := 0
		for n%i == 0 {
			exp++
			n /= i
		}

		if exp == 0 {
			continue
		}
		p[i] = exp
	}
	if n > 1 {
		p[n] = 1
	}

	return p
}

// IsPrime judges whether an argument integer is a prime number or not.
func IsPrime(n int) bool {
	if n == 1 {
		return false
	}

	for i := 2; i*i <= n; i++ {
		if n%i == 0 {
			return false
		}
	}

	return true
}

/*********** Inverse Element ***********/

// CalcNegativeMod can calculate a right residual whether value is positive or negative.
func CalcNegativeMod(val, m int) int {
	res := val % m
	if res < 0 {
		res += m
	}
	return res
}

func modpow(a, e, m int) int {
	if e == 0 {
		return 1
	}

	if e%2 == 0 {
		halfE := e / 2
		half := modpow(a, halfE, m)
		return half * half % m
	}

	return a * modpow(a, e-1, m) % m
}

// CalcModInv returns $a^{-1} mod m$ by Fermat's little theorem.
func CalcModInv(a, m int) int {
	return modpow(a, m-2, m)
}

/********** sort package (snippets) **********/
//sort.Sort(sort.IntSlice(s))
//sort.Sort(sort.Reverse(sort.IntSlice(s)))
//sort.Sort(sort.Float64Slice(s))
//sort.Sort(sort.StringSlice(s))

// struct sort
type Mono struct {
	key, value int
}
type MonoList []*Mono

func (ml MonoList) Len() int {
	return len(ml)
}
func (ml MonoList) Swap(i, j int) {
	ml[i], ml[j] = ml[j], ml[i]
}
func (ml MonoList) Less(i, j int) bool {
	return ml[i].value < ml[j].value
}

// Example(ABC111::C)
//oddCountList, evenCountList := make(MonoList, 1e5+1), make(MonoList, 1e5+1)
//for i := 0; i <= 1e5; i++ {
//	oddCountList[i] = &Mono{key: i, value: oddMemo[i]}
//	evenCountList[i] = &Mono{key: i, value: evenMemo[i]}
//}
//sort.Sort(sort.Reverse(oddCountList))		// DESC sort
//sort.Sort(sort.Reverse(evenCountList))	// DESC sort

/********** copy function (snippets) **********/
//a = []int{0, 1, 2}
//b = make([]int, len(a))
//copy(b, a)

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

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()

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

const MOD = 1000000000 + 7
const ALPHABET_NUM = 26

var a, b, c int

func main() {
	a, b, c = ReadInt(), ReadInt(), ReadInt()
	if a+b == c || b+c == a || c+a == b {
		fmt.Println("Yes")
	} else {
		fmt.Println("No")
	}
}

Score : 100 points

Problem Statement

Two students of AtCoder Kindergarten are fighting over candy packs.

There are three candy packs, each of which contains a, b, and c candies, respectively.

Teacher Evi is trying to distribute the packs between the two students so that each student gets the same number of candies. Determine whether it is possible.

Note that Evi cannot take candies out of the packs, and the whole contents of each pack must be given to one of the students.

Constraints

1 ≦ a, b, c ≦ 100

Input

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

a b c

Output

If it is possible to distribute the packs so that each student gets the same number of candies, print Yes. Otherwise, print No.

Sample Input 1

10 30 20

Sample Output 1

Yes

Give the pack with 30 candies to one student, and give the two packs with 10 and 20 candies to the other. Then, each gets 30 candies.

Sample Input 2

30 30 100

Sample Output 2

No

In this case, the student who gets the pack with 100 candies always has more candies than the other.

Note that every pack must be given to one of them.

Sample Input 3

56 25 31

Sample Output 3

Yes


package main

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

func main() {
	W, H, N := ReadInt(), ReadInt(), ReadInt()

	sx, sy := 0, 0
	tx, ty := W, H

	for i := 0; i < N; i++ {
		x, y, a := ReadInt(), ReadInt(), ReadInt()
		switch a {
		case 1:
			sx = Max(sx, x)
		case 2:
			tx = Min(tx, x)
		case 3:
			sy = Max(sy, y)
		case 4:
			ty = Min(ty, y)
		}

		if tx <= sx || ty <= sy {
			fmt.Println(0)
			return
		}
	}
	fmt.Println((tx - sx) * (ty - sy))
}

func Min(xs ...int) int {
	min := xs[0]
	for _, x := range xs[1:] {
		if min > x {
			min = x
		}
	}
	return min
}
func Max(xs ...int) int {
	max := xs[0]
	for _, x := range xs[1:] {
		if max < x {
			max = x
		}
	}
	return max
}

var sc = bufio.NewScanner(os.Stdin)

func init()        { sc.Buffer(make([]byte, 256), 1e9); sc.Split(bufio.ScanWords) }
func Read() string { sc.Scan(); return sc.Text() }

func ReadInt() int {
	v, e := strconv.Atoi(Read())
	if e != nil {
		panic(e.Error())
	}
	return v
}

Score : 200 points

Problem Statement

There is a rectangle in the xy-plane, with its lower left corner at (0, 0) and its upper right corner at (W, H). Each of its sides is parallel to the x-axis or y-axis. Initially, the whole region within the rectangle is painted white.

Snuke plotted N points into the rectangle. The coordinate of the i-th (1 ≦ i ≦ N) point was (x_i, y_i).

Then, he created an integer sequence a of length N, and for each 1 ≦ i ≦ N, he painted some region within the rectangle black, as follows:

If a_i = 1, he painted the region satisfying x < x_i within the rectangle.

If a_i = 2, he painted the region satisfying x > x_i within the rectangle.

If a_i = 3, he painted the region satisfying y < y_i within the rectangle.

If a_i = 4, he painted the region satisfying y > y_i within the rectangle.

Find the area of the white region within the rectangle after he finished painting.

Constraints

1 ≦ W, H ≦ 100

1 ≦ N ≦ 100

0 ≦ x_i ≦ W (1 ≦ i ≦ N)

0 ≦ y_i ≦ H (1 ≦ i ≦ N)

W, H (21:32, added), x_i and y_i are integers.

a_i (1 ≦ i ≦ N) is 1, 2, 3 or 4.

Input

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

W H N
x_1 y_1 a_1
x_2 y_2 a_2
:
x_N y_N a_N

Output

Print the area of the white region within the rectangle after Snuke finished painting.

Sample Input 1

5 4 2
2 1 1
3 3 4

Sample Output 1

9

The figure below shows the rectangle before Snuke starts painting.

First, as (x_1, y_1) = (2, 1) and a_1 = 1, he paints the region satisfying x < 2 within the rectangle:

Then, as (x_2, y_2) = (3, 3) and a_2 = 4, he paints the region satisfying y > 3 within the rectangle:

Now, the area of the white region within the rectangle is 9.

Sample Input 2

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

Sample Output 2

0

It is possible that the whole region within the rectangle is painted black.

Sample Input 3

10 10 5
1 6 1
4 1 3
6 9 4
9 4 2
3 1 3

Sample Output 3

64


package main

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

var sc = bufio.NewScanner(os.Stdin)

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

func init() {
	sc.Split(bufio.ScanWords)
}

func max(x, y int) int {
	if x > y {
		return x
	}
	return y
}

func main() {
	w, h, n := scanInt(), scanInt(), scanInt()

	xl, xr := 0, w
	yl, yr := 0, h
	for i := 0; i < n; i++ {
		x, y, a := scanInt(), scanInt(), scanInt()
		switch a {
		case 1:
			xl = x
		case 2:
			xr = x
		case 3:
			yl = y
		case 4:
			yr = y
		}
	}
	fmt.Println(max((xr-xl)*(yr-yl), 0))
}


package main

import "fmt"

func main() {
	var n int
	var s, t string
	fmt.Scan(&n, &s, &t)

	ans := ""
	for i := 0; i <= n; i++ {
		tmp := s + t[i:]
		if tmp[len(tmp)-n:] == t {
			ans = tmp
		}
	}

	fmt.Println(len(ans))
}

Score : 200 points

Problem Statement

Snuke is interested in strings that satisfy the following conditions:

The length of the string is at least N.

The first N characters equal to the string s.

The last N characters equal to the string t.

Find the length of the shortest string that satisfies the conditions.

Constraints

1≤N≤100

The lengths of s and t are both N.

s and t consist of lowercase English letters.

Input

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

N
s
t

Output

Print the length of the shortest string that satisfies the conditions.

Sample Input 1

3
abc
cde

Sample Output 1

5

The shortest string is abcde.

Sample Input 2

1
a
z

Sample Output 2

2

The shortest string is az.

Sample Input 3

4
expr
expr

Sample Output 3

4

The shortest string is expr.


package main

import "fmt"

func main() {
	var a, b, c int
	fmt.Scan(&a, &b, &c)
	if a == b && b == c {
		fmt.Println("1")
	} else if a != b && b!= c && a != c {
		fmt.Println("3")
	} else {
		fmt.Println("2")
	}
}

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 "fmt"

func main() {
	var N, K int
	fmt.Scan(&N, &K)

	patterns := K
	for i := 1; i < N; i++ {
		patterns *= K - 1
	}

	fmt.Println(patterns)
}

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"
)

var N, K int
var ans int = 1

func main() {
	fmt.Scan(&N, &K)

	ans *= K
	for i := 1; i < N; i++ {
		ans *= (K - 1)
	}
	fmt.Println(ans)
}

/*  ----------------------------------------  */

func gcd(x, y uint64) uint64 {
	if x%y == 0 {
		return y
	} else {
		r := x % y
		return gcd(y, r)
	}
}

func combination(x, y int) int {
	return permutation(x, y) / permutation(y, y)
}

func permutation(x, y int) int {
	var ans int = 1
	for i := x - y; 0 < i; i-- {
		ans *= i
	}
	return ans
}

func max(x ...int) int {
	var res int = x[0]
	for i := 1; i < len(x); i++ {
		res = int(math.Max(float64(x[i]), float64(res)))
	}
	return res
}

func min(x ...int) int {
	var res int = x[0]
	for i := 1; i < len(x); i++ {
		res = int(math.Min(float64(x[i]), float64(res)))
	}
	return res
}
func pow(x, y int) int { return int(math.Pow(float64(x), float64(y))) }
func abs(x int) int    { return int(math.Abs(float64(x))) }
func floor(x int) int  { return int(math.Floor(float64(x))) }

type XY struct {
	x int
	y int
}

type SortBy [][]int

func (a SortBy) Len() int      { return len(a) }
func (a SortBy) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a SortBy) Less(i, j int) bool {
	return a[i][1] < a[j][1]
}


package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

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

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

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

// Sort
type RuneSlice []rune

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

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	t, a := sc.nextInt(), sc.nextInt()
	for i := 1; i < N; i++ {
		nt, na := sc.nextInt(), sc.nextInt()
		m := max(ceil(t, nt), ceil(a, na))
		t = nt * m
		a = na * m
	}

	fmt.Fprintln(wtr, t+a)
	wtr.Flush()
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

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"
	"bufio"
	"os"
	"strconv"
)

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()
	N := sc.NextInt()
	K := sc.NextInt()
	P := make([]byte, 26)
	for i := 0; i < N; i++ {
		P[sc.NextLine()[0] - 'A']++
	}
	count := 0
	for {
		choice := 0
		for i := 0; i < 26; i++ {
			if P[i] > 0 {
				choice++
				P[i]--
				if choice == K {
					break
				}
			}
		}
		if choice < K {
			break
		}
		count++
	}
	fmt.Println(count)
}

Score : 100 points

Problem Statement

Kyoto University Programming Contest is a programming contest voluntarily held by some Kyoto University students.
This contest is abbreviated as Kyoto University Programming Contest and called KUPC.

source: Kyoto University Programming Contest Information

The problem-preparing committee met to hold this year's KUPC and N problems were proposed there.
The problems are numbered from 1 to N and the name of i-th problem is P_i.
However, since they proposed too many problems, they decided to divide them into some sets for several contests.

They decided to divide this year's KUPC into several KUPCs by dividing problems under the following conditions.

One KUPC provides K problems.

Each problem appears at most once among all the KUPCs.

All the first letters of the problem names in one KUPC must be different.

You, one of the committee members, want to hold as many KUPCs as possible.
Write a program to find the maximum number of KUPCs that can be held this year.

Constraints

1 \leq N \leq 10^4

1 \leq K \leq 26

1 \leq |P_i| \leq 10

All characters in P_i are capital letters.

Note that, for each i and j (1 \leq i < j \leq N),
P_i \neq P_j are not necessarily satisfied.

Input

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

N K
P_1
:
P_N

Output

Print the maximum number of KUPCs that can be held on one line.

Sample Input 1

9 3
APPLE
ANT
ATCODER
BLOCK
BULL
BOSS
CAT
DOG
EGG

For example, three KUPCs can be held by dividing the problems as follows.

First: APPLE, BLOCK, CAT

Second: ANT, BULL, DOG

Third: ATCODER, BOSS, EGG

Sample Output 1

3

Sample Input 2

3 2
KU
KYOUDAI
KYOTOUNIV

Sample Output 2

0

No KUPC can be held.


package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
)

func scanBytes(scanner *bufio.Scanner) (bs []byte) {
	if scanner.Scan() {
		return scanner.Bytes()
	}
	return
}

func main() {
	buf := make([]byte, 262144)

	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(buf, cap(buf))
	scanner.Split(bufio.ScanWords)

	x := scanBytes(scanner) // 2 <= |x| <= 200,000
	list := list.New()
	for _, b := range x {
		if b == 'S' || list.Len() == 0 {
			list.PushBack(b) // 'S' or 'T'
			continue
		}
		// b == 'T':
		if back := list.Back(); back.Value.(byte) == 'S' {
			list.Remove(back)
			continue
		}
		list.PushBack(b)
	}
	fmt.Println(list.Len())
}

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 (
	"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 powInt(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
}

func sumInts(x []int) int {

	total := 0
	for _, v := range x {
		total += v
	}

	return total
}

//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 N int

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

	N = nextInt()
	a := make([]int, N)
	for i := 0; i < N; i++ {
		a[i] = nextInt()
	}

	ans := 0
	for i := 0; i < N; i++ {
		if a[a[i]-1] == i+1 {
			ans++
		}
	}
	fmt.Println(ans / 2)
}

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).


package main

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

func out(x ...interface{}) {
	fmt.Println(x...)
}

var sc = bufio.NewScanner(os.Stdin)

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

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

func main() {
	sc.Split(bufio.ScanWords)
	sc.Buffer([]byte{}, 100100)

	s := []byte(getString())
	K := getInt()

	for i := 0; i < len(s); i++ {
		if s[i] == 'a' {
			continue
		}
		v := s[i]
		d := int(1 + 'z' - v)
		//out(d)
		if K >= d {
			K -= d
			s[i] = 'a'
		}
	}
	//out(K)
	K %= 26
	l := len(s) - 1
	s[l] += byte(K)
	if s[l] > 'z' {
		s[l] = 'a'
	}
	out(string(s))

}

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"
)

func main() {
	var sa, sb, sc string
	fmt.Scan(&sa, &sb, &sc)

	t := sa[0]
	for {
		switch t {
		case 'a':
			if len(sa) == 0 {
				fmt.Println("A")
				return
			}
			t = sa[0]
			sa = sa[1:]
		case 'b':
			if len(sb) == 0 {
				fmt.Println("B")
				return
			}
			t = sb[0]
			sb = sb[1:]
		case 'c':
			if len(sc) == 0 {
				fmt.Println("C")
				return
			}
			t = sc[0]
			sc = sc[1:]
		}
	}
}

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


package main

import (
	"fmt"
	"math"
)

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

	num := make([]int, len(S))
	for i, r := range S {
		num[i] = int(r - '0')
	}

	arr := make([]int, 0, (1 << uint(len(S))))
	for bit := 0; bit < (1 << uint(len(S)-1)); bit++ {
		s := 0
		for i := 0; i < len(S); i++ {
			if bit&(1<<uint(i)) == (1 << uint(i)) {
				p := pow(num[s : i+1])
				arr = append(arr, p)
				s = i + 1
			}
		}
		arr = append(arr, pow(num[s:len(num)]))
	}

	sum := 0
	for i := range arr {
		sum += arr[i]
	}
	fmt.Println(sum)

}

func pow(data []int) int {
	if len(data) == 1 {
		return data[0]
	}

	sum := 0
	for i := 0; i < len(data); i++ {
		sum += data[i] * int(math.Pow10(len(data)-i-1))
	}
	return sum
}

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