func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int k;     cin >> k;     string s;     cin >> s;     int n = s.size();     int ps[n + 5];     ps[0] = s[0] -  0 ;     for (int i = 1; i < n; i++) ps[i] = ps[i - 1] + s[i] -  0 ;     long long ans = 0;     for (int i = 0; i < n; i++) {       int it1 = lower_bound(ps + i, ps + n, (i ? ps[i - 1] : 0) + k) - ps;       if (it1 == n) continue;       int it2 = lower_bound(ps + i, ps + n, (i ? ps[i - 1] : 0) + k + 1) - 1 - ps;       ans += it2 - it1 + 1;     }     cout << ans <<   n ;   }   