func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 2e5 + 9;   char s[MAXN];   map<char, char> mp;   int main(int argc, char const *argv[]) {     int n, m;     scanf( %d%d , &n, &m);     scanf( %s , s);     int present = 0;     for (int i = 0; i < n; i++) {       present |= (1 << (s[i] -  a ));     }     for (char c =  a ; c <=  z ; c++)       if (present & (1 << (c -  a ))) {         mp[c] = c;       }     char one, two;     for (int i = 0; i < m; i++) {       scanf(  %c %c , &one, &two);       if (one == two) {         continue;       }       for (auto &it : mp) {         if (it.second == one)           it.second = two;         else if (it.second == two)           it.second = one;       }     }     for (int i = 0; i < n; i++)       if (mp.count(s[i])) {         s[i] = mp[s[i]];       }     puts(s);     return 0;   }   