func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     string a, b;     cin >> a >> b;     int l = b.size();     int st = a.size() - 1;     int ar[l + 3];     memset(ar, -1, sizeof ar);     ar[l] = st + 1;     for (int i = l - 1; i >= 0; i--) {       while (st >= 0 && a[st] != b[i]) {         st--;       }       if (st >= 0) {         ar[i] = st;         st--;       } else         break;     }     int ans = 0;     int pre = 0;     for (int i = 0; i < a.size(); i++) {       int la = ar[pre];       if (la != -1) ans = max(ans, la - i);       if (pre < l && a[i] == b[pre]) {         pre++;       }     }     cout << ans << endl;     return 0;   }   