func_code_string: #include <bits/stdc++.h>   using namespace std;   string lower(string second) {     for (int i = 0; i < second.size(); i++)       if (second[i] >=  A  && second[i] <=  Z ) second[i] = second[i] -  A  +  a ;     return second;   }   char reg(char c, char t) {     if (c >=  A  && c <=  Z ) return t -  a  +  A ;     return t;   }   string second, a[105], sl;   bool u[105];   int n;   int main() {     cin >> n;     for (int i = 0; i < n; i++) {       cin >> a[i];       a[i] = lower(a[i]);     }     char let;     cin >> second >> let;     sl = lower(second);     for (int i = 0; i < second.size(); i++)       for (int j = 0; j < n; j++)         if (i + a[j].size() <= second.size() &&             sl.substr(i, a[j].size()) == a[j]) {           for (int k = i; k < i + a[j].size(); k++) u[k] = true;         }     for (int i = 0; i < second.size(); i++)       if (u[i]) {         if (sl[i] == let) {           if (sl[i] ==  a )             second[i] = reg(second[i],  b );           else             second[i] = reg(second[i],  a );         } else           second[i] = reg(second[i], let);       }     cout << second;     return 0;   }   