func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     vector<char> vec(100001);     vec[0] =  a ;     int i = 1;     while (i < 100001) {       if (vec[i - 1] ==  a )         vec[i] =  b ;       else if (vec[i - 1] ==  b )         vec[i] =  c ;       else if (vec[i - 1] ==  c )         vec[i] =  d ;       else if (vec[i - 1] ==  d )         vec[i] =  a ;       i++;     }     int n;     cin >> n;     for (int i = 0; i < n; i++) cout << vec[i];     cout << endl;   }   