func_code_string: #include <bits/stdc++.h>   using namespace std;   int Set(int N, int pos) { return N = N | (1 << pos); }   int reset(int N, int pos) { return N = N & ~(1 << pos); }   bool check(long long N, int pos) { return (bool)(N & (1LL << pos)); }   int n, m, l, r;   string s;   char c1, c2;   int main() {     cin >> n >> m;     cin >> s;     for (int i = 1; i <= m; i++) {       cin >> l >> r >> c1 >> c2;       l--, r--;       for (int j = l; j <= r; j++) {         if (s[j] == c1) s[j] = c2;       }     }     cout << s << endl;     return 0;   }   