func_code_string: #include <bits/stdc++.h>   using namespace std;   string a, b;   int rs, p;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     cin >> a >> b;     if (a.size() != b.size()) return cout <<  NO , 0;     for (int i = 0; i < a.size(); i++)       if (a[i] != b[i]) rs++, p = i;     if (rs != 2) return cout <<  NO , 0;     for (int i = 0; i < a.size(); i++)       if (a[i] != b[i] && a[i] == b[p] && a[p] == b[i])         return cout <<  YES , 0;       else if (a[i] != b[i])         return cout <<  NO , 0;   }   