func_code_string: #include <bits/stdc++.h>   using namespace std;   int a[1000005];   queue<long long int> q;   vector<long long int> v;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     long long int i, j, k, n, m, mid;     cin >> k;     string s;     cin >> s;     n = s.size();     int co = 0;     long long int sum = 0;     if (k == 0) {       for (i = 0; i < n; i++) {         if (s[i] ==  0 ) {           co++;         } else           co = 0;         sum += (co);       }       cout << sum;       return 0;     }     for (i = 0; i < n; i++) {       if (s[i] ==  1 ) {         a[i] = co;         co = 0;         v.push_back(i);       } else         co++;     }     long long int first = 0;     long long int l = v.size();     for (i = k - 1; i < l; i++) {       long long int temp1 = a[v[first]] + 1;       long long int temp2;       if (i + 1 < l)         temp2 = v[i + 1] - v[i];       else         temp2 = n - v[i];       sum += temp1 * temp2;       first++;     }     cout << sum;     return 0;   }   