func_code_string: #include <bits/stdc++.h>   using namespace std;   const int inf = 1e9 + 7;   const long long llinf = 1e18 + 7;   const double eps = 1e-15;   const int N = 2e5 + 5;   int cnt0[N], cnt1[N];   long long sum(int cnt[N], int l, int r) {     long long ret = cnt[r];     if (l) ret -= cnt[l - 1];     return ret;   }   int main() {     string a, b;     cin >> a >> b;     memset(cnt0, 0, sizeof cnt0);     memset(cnt1, 0, sizeof cnt1);     for (int i = 0; i < b.size(); ++i) {       cnt0[i] += b[i] ==  0 ;       if (i) cnt0[i] += cnt0[i - 1];       cnt1[i] += b[i] ==  1 ;       if (i) cnt1[i] += cnt1[i - 1];     }     long long ans = 0;     for (int i = 0; i < a.size(); ++i) {       int lastloc = int(b.size()) - int(a.size()) + i;       if (a[i] ==  1 ) {         ans += sum(cnt0, i, lastloc);       } else         ans += sum(cnt1, i, lastloc);     }     cout << ans << endl;     return 0;   }   