func_code_string: #include <bits/stdc++.h>   using namespace std;   string vow =  aeiou ;   const int dxhorse[] = {-2, -2, -1, -1, 1, 1, 2, 2};   const int dyhorse[] = {1, -1, 2, -2, 2, -2, 1, -1};   const int dx[] = {-1, 0, 0, 1};   const int dy[] = {0, -1, 1, 0};   const long double pie = 3.14159265358979;   const long long mod = 1e9 + 7;   void solve(int test_case) {     int k;     cin >> k;     string s;     cin >> s;     int n = s.size();     vector<int> pref(n + 1);     for (int i = 1; i < n + 1; i++) pref[i] = pref[i - 1] + s[i - 1] -  0 ;     long long ans = 0;     for (int i = 0; i < n; i++) {       int x = pref[i + 1];       int val = x - k;       if (val < 0) continue;       ;       int ans_indx = -1;       for (int lo = 0, hi = i; lo <= hi;) {         int mid = lo + hi >> 1;         if (pref[mid] > val)           hi = mid - 1;         else if (pref[mid] == val)           ans_indx = mid, hi = mid - 1;         else           lo = mid + 1;       }       if (ans_indx == -1) continue;       ;       long long L = ans_indx;       ans_indx = -1;       for (int lo = 0, hi = i; lo <= hi;) {         int mid = lo + hi >> 1;         if (pref[mid] == val)           ans_indx = mid, lo = mid + 1;         else if (pref[mid] < val)           lo = mid + 1;         else           hi = mid - 1;       }       if (ans_indx == -1) continue;       ;       long long R = ans_indx;       ans += R - L + 1;     }     cout << ans;     cout <<   n ;   }   int main() {     int t = 1;     for (int i = 0; i < t; i++) solve(i);     return 0;   }   