func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, m;     cin >> n >> m;     string test;     cin >> test;     for (int i = 0; i < m; i++) {       int l, r;       char c1, c2;       cin >> l >> r >> c1 >> c2;       l -= 1;       r -= 1;       for (; l <= r; l++) {         if (test[l] == c1) {           test[l] = c2;         }       }     }     cout << test << endl;     return 0;   }   