func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long i, a = 0, b, j, b1[26] = {}, b2[26] = {};     string s1, s2;     vector<long> v1, v2;     cin >> s1 >> s2;     if (s1.size() != s2.size()) {       cout <<  NO ;       return 0;     }     for (i = 0; i < s1.size(); i++) {       if (s1[i] != s2[i]) {         a++;         v1.push_back(i);       }     }     if (a != 2) {       cout <<  NO ;       return 0;     }     if ((s1[v1[0]] == s2[v1[1]]) && (s2[v1[0]] == s1[v1[1]]))       cout <<  YES ;     else       cout <<  NO ;     return 0;   }   