func_code_string: #include <bits/stdc++.h>   using namespace std;   string a, b, c, d;   int pref[123456];   int main() {     int n, k;     cin >> n >> k;     string s;     cin >> s;     s =  .  + s;     for (int i = 1; i < s.length(); i++) {       pref[i] = pref[i - 1];       if (s[i] ==  0 ) pref[i]++;     }     int ans = INT_MAX;     for (int i = 1; i < s.length(); i++) {       if (s[i] ==  0 ) {         int lo = k / 2;         int hi = s.length() - 1;         while (hi - lo > 2) {           int mid = (lo + hi) / 2;           int lft = max(0, i - mid);           int cccc = s.length() - 1;           int rt = min(cccc, i + mid);           if (pref[rt] - pref[lft - 1] < k + 1)             lo = mid;           else             hi = mid;         }         while (lo <= hi) {           int lft = max(0, i - lo);           int cccc = s.length() - 1;           int rt = min(cccc, i + lo);           if (pref[rt] - pref[lft - 1] < k + 1) lo++;           if (pref[rt] - pref[lft - 1] >= k + 1) break;         }         ans = min(ans, lo);       }     }     cout << ans;   }   