Language: C++

#include <bits/stdc++.h>
using namespase std;

int main(){
  int a,b;
  cin >> a >> b;
  char c;
  string ans = "";
  for(int i = 0;i < a;i++){
    cin >> c;
    if(i == b-1){
      if(c == 'A'){
        ans += "a";
      }else if(c == 'B'){
        ans += "b";
      }else if(c == 'C'){
        ans += "c";
      }
    }else{
      ans += c;
    }
  }
  cout << ans << endl;
}


Compiler output:
a.cc:2:7: error: expected nested-name-specifier before 'namespase'
    2 | using namespase std;
      |       ^~~~~~~~~
a.cc: In function 'int main()':
a.cc:6:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |   cin >> a >> b;
      |   ^~~
      |   std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146,
                 from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:8:3: error: 'string' was not declared in this scope
    8 |   string ans = "";
      |   ^~~~~~
a.cc:8:3: note: suggested alternatives:
In file included from /usr/include/c++/14/string:41,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:13:9: error: 'ans' was not declared in this scope; did you mean 'abs'?
   13 |         ans += "a";
      |         ^~~
      |         abs
a.cc:15:9: error: 'ans' was not declared in this scope; did you mean 'abs'?
   15 |         ans += "b";
      |         ^~~
      |         abs
a.cc:17:9: error: 'ans' was not declared in this scope; did you mean 'abs'?
   17 |         ans += "c";
      |         ^~~
      |         abs
a.cc:20:7: error: 'ans' was not declared in this scope; did you mean 'abs'?
   20 |       ans += c;
      |       ^~~
      |       abs
a.cc:23:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   23 |   cout << ans << endl;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:23:11: error: 'ans' was not declared in this scope; did you mean 'abs'?
   23 |   cout << ans << endl;
      |           ^~~
      |           abs
a.cc:23:18: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   23 |   cout << ans << endl;
      |                  ^~~~
      |                  std::endl
In file included from /usr/include/c++/14/istream:41,
                 from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~