VeriContest_Lite / leetcode /lc1589 /code_spec.rs
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use vstd::prelude::*;
fn main() {}
verus! {
pub struct Solution;
impl Solution {
pub open spec fn freq_at(requests: Seq<Vec<i32>>, idx: int, k: int) -> int
decreases requests.len() - k
{
if k >= requests.len() as int {
0
} else {
(if requests[k]@[0] as int <= idx && idx <= requests[k]@[1] as int {
1int
} else {
0int
}) + Self::freq_at(requests, idx, k + 1)
}
}
pub open spec fn freq_vec(requests: Seq<Vec<i32>>, n: int) -> Seq<int> {
Seq::new(n as nat, |i: int| Self::freq_at(requests, i, 0))
}
pub open spec fn to_int_seq(s: Seq<i32>) -> Seq<int> {
Seq::new(s.len(), |i: int| s[i] as int)
}
pub open spec fn dot_product_int(a: Seq<int>, b: Seq<int>, k: int) -> int
decreases a.len() - k
{
if k >= a.len() as int {
0
} else {
a[k] * b[k] + Self::dot_product_int(a, b, k + 1)
}
}
pub open spec fn is_sorted_int(s: Seq<int>) -> bool {
forall |i: int, j: int| 0 <= i <= j < s.len() ==> s[i] <= s[j]
}
pub open spec fn count_int(s: Seq<int>, v: int) -> int
decreases s.len()
{
if s.len() == 0 {
0
} else {
(if s.last() == v { 1int } else { 0int })
+ Self::count_int(s.drop_last(), v)
}
}
pub open spec fn is_perm_int(a: Seq<int>, b: Seq<int>) -> bool {
a.len() == b.len()
&& forall |v: int| Self::count_int(a, v) == Self::count_int(b, v)
}
pub open spec fn to_int_seq_i64(s: Seq<i64>) -> Seq<int> {
Seq::new(s.len(), |i: int| s[i] as int)
}
pub open spec fn count_occ(s: Seq<i32>, val: i32) -> int
decreases s.len()
{
if s.len() == 0 { 0 }
else {
(if s.last() == val { 1int } else { 0int })
+ Self::count_occ(s.drop_last(), val)
}
}
pub open spec fn is_perm(a: Seq<i32>, b: Seq<i32>) -> bool {
a.len() == b.len()
&& forall |v: i32| Self::count_occ(a, v) == Self::count_occ(b, v)
}
pub open spec fn is_sorted(s: Seq<i32>) -> bool {
forall |i: int, j: int| 0 <= i <= j < s.len() ==> s[i] <= s[j]
}
pub open spec fn count_occ_i64(s: Seq<i64>, val: i64) -> int
decreases s.len()
{
if s.len() == 0 { 0 }
else {
(if s.last() == val { 1int } else { 0int })
+ Self::count_occ_i64(s.drop_last(), val)
}
}
pub open spec fn is_perm_i64(a: Seq<i64>, b: Seq<i64>) -> bool {
a.len() == b.len()
&& forall |v: i64| Self::count_occ_i64(a, v) == Self::count_occ_i64(b, v)
}
pub open spec fn is_sorted_i64(s: Seq<i64>) -> bool {
forall |i: int, j: int| 0 <= i <= j < s.len() ==> s[i] <= s[j]
}
fn ms_merge(a: &Vec<i32>, b: &Vec<i32>) -> (result: Vec<i32>)
requires Self::is_sorted(a@), Self::is_sorted(b@)
ensures
Self::is_sorted(result@),
result@.len() == a@.len() + b@.len(),
Self::is_perm(result@, a@ + b@),
{
let mut result: Vec<i32> = Vec::new();
let mut i: usize = 0;
let mut j: usize = 0;
while i < a.len() || j < b.len()
{
if i < a.len() && (j >= b.len() || a[i] <= b[j]) {
result.push(a[i]);
i = i + 1;
} else {
result.push(b[j]);
j = j + 1;
}
}
result
}
fn ms_sort(input: &Vec<i32>) -> (result: Vec<i32>)
ensures
Self::is_sorted(result@),
result@.len() == input@.len(),
Self::is_perm(result@, input@),
decreases input.len(),
{
let n = input.len();
if n <= 1 {
let mut result = Vec::new();
if n == 1 {
result.push(input[0]);
}
return result;
}
let mid = n / 2;
let mut left: Vec<i32> = Vec::new();
let mut i: usize = 0;
while i < mid
{
left.push(input[i]);
i = i + 1;
}
let mut right: Vec<i32> = Vec::new();
let mut j: usize = mid;
while j < n
{
right.push(input[j]);
j = j + 1;
}
let sorted_left = Self::ms_sort(&left);
let sorted_right = Self::ms_sort(&right);
let result = Self::ms_merge(&sorted_left, &sorted_right);
result
}
fn ms_merge_i64(a: &Vec<i64>, b: &Vec<i64>) -> (result: Vec<i64>)
requires Self::is_sorted_i64(a@), Self::is_sorted_i64(b@)
ensures
Self::is_sorted_i64(result@),
result@.len() == a@.len() + b@.len(),
Self::is_perm_i64(result@, a@ + b@),
{
let mut result: Vec<i64> = Vec::new();
let mut i: usize = 0;
let mut j: usize = 0;
while i < a.len() || j < b.len()
{
if i < a.len() && (j >= b.len() || a[i] <= b[j]) {
result.push(a[i]);
i = i + 1;
} else {
result.push(b[j]);
j = j + 1;
}
}
result
}
fn ms_sort_i64(input: &Vec<i64>) -> (result: Vec<i64>)
ensures
Self::is_sorted_i64(result@),
result@.len() == input@.len(),
Self::is_perm_i64(result@, input@),
decreases input.len(),
{
let n = input.len();
if n <= 1 {
let mut result = Vec::new();
if n == 1 {
result.push(input[0]);
}
return result;
}
let mid = n / 2;
let mut left: Vec<i64> = Vec::new();
let mut i: usize = 0;
while i < mid
{
left.push(input[i]);
i = i + 1;
}
let mut right: Vec<i64> = Vec::new();
let mut j: usize = mid;
while j < n
{
right.push(input[j]);
j = j + 1;
}
let sorted_left = Self::ms_sort_i64(&left);
let sorted_right = Self::ms_sort_i64(&right);
let result = Self::ms_merge_i64(&sorted_left, &sorted_right);
result
}
pub fn max_sum_range_query(nums: Vec<i32>, requests: Vec<Vec<i32>>) -> (result: i32)
requires
1 <= nums@.len() <= 100_000,
forall |i: int| 0 <= i < nums@.len() ==>
0 <= #[trigger] nums@[i] <= 100_000,
1 <= requests@.len() <= 100_000,
forall |i: int| 0 <= i < requests@.len() ==> (
(#[trigger] requests@[i])@.len() == 2
&& 0 <= requests@[i]@[0]
&& requests@[i]@[0] <= requests@[i]@[1]
&& (requests@[i]@[1] as int) < nums@.len() as int
),
ensures
0 <= result < 1_000_000_007,
exists |sv: Seq<int>, sf: Seq<int>|
sv.len() == nums@.len()
&& sf.len() == nums@.len()
&& Self::is_sorted_int(sv)
&& Self::is_sorted_int(sf)
&& Self::is_perm_int(sv, Self::to_int_seq(nums@))
&& Self::is_perm_int(sf, Self::freq_vec(requests@, nums@.len() as int))
&& result as int
== Self::dot_product_int(sv, sf, 0) % 1_000_000_007
&& forall |c: Seq<int>|
c.len() == sv.len() && Self::is_perm_int(c, sv)
==> Self::dot_product_int(sv, sf, 0)
>= Self::dot_product_int(c, sf, 0),
{
let n = nums.len();
let m = requests.len();
let modval: i64 = 1_000_000_007;
let mut diff: Vec<i64> = Vec::new();
let mut z: usize = 0;
while z < n {
diff.push(0);
z = z + 1;
}
let mut r: usize = 0;
while r < m {
let s = requests[r][0] as usize;
let e = requests[r][1] as usize;
diff.set(s, diff[s] + 1);
if e + 1 < n {
diff.set(e + 1, diff[e + 1] - 1);
}
r = r + 1;
}
let mut count: Vec<i64> = Vec::new();
let mut running: i64 = 0;
let mut idx: usize = 0;
while idx < n {
running = running + diff[idx];
count.push(running);
idx = idx + 1;
}
let nums = Self::ms_sort(&nums);
let sorted_count = Self::ms_sort_i64(&count);
let mut result: i64 = 0;
let mut k: usize = 0;
while k < n {
result = (result + nums[k] as i64 * sorted_count[k]) % modval;
k = k + 1;
}
result as i32
}
}
}