Language: C++

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define INF 1LL<<62
#define inf 1000000007

int main() {
	string s;
	cin>>s;
	map<string,ll>a;
	for(ll i=0;i<s.size();i++){
		a[s[i]]++;
	}
	bool ch=true;
	for(ll itr=a.begin();itr!=a.end();itr++){
		ll val=itr->second;
		if(val!=2){
			ch=false;
		}
    }
    cout << (ch?"Yes":"No");
	// your code goes here
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:12:18: error: no match for 'operator[]' (operand types are 'std::map<std::__cxx11::basic_string<char>, long long int>' and '__gnu_cxx::__alloc_traits<std::allocator<char>, char>::value_type' {aka 'char'})
   12 |                 a[s[i]]++;
      |                  ^
In file included from /usr/include/c++/14/map:63,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:152,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_map.h:504:7: note: candidate: 'std::map<_Key, _Tp, _Compare, _Alloc>::mapped_type& std::map<_Key, _Tp, _Compare, _Alloc>::operator[](const key_type&) [with _Key = std::__cxx11::basic_string<char>; _Tp = long long int; _Compare = std::less<std::__cxx11::basic_string<char> >; _Alloc = std::allocator<std::pair<const std::__cxx11::basic_string<char>, long long int> >; mapped_type = long long int; key_type = std::__cxx11::basic_string<char>]'
  504 |       operator[](const key_type& __k)
      |       ^~~~~~~~
/usr/include/c++/14/bits/stl_map.h:504:34: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<char>, char>::value_type' {aka 'char'} to 'const std::map<std::__cxx11::basic_string<char>, long long int>::key_type&' {aka 'const std::__cxx11::basic_string<char>&'}
  504 |       operator[](const key_type& __k)
      |                  ~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_map.h:524:7: note: candidate: 'std::map<_Key, _Tp, _Compare, _Alloc>::mapped_type& std::map<_Key, _Tp, _Compare, _Alloc>::operator[](key_type&&) [with _Key = std::__cxx11::basic_string<char>; _Tp = long long int; _Compare = std::less<std::__cxx11::basic_string<char> >; _Alloc = std::allocator<std::pair<const std::__cxx11::basic_string<char>, long long int> >; mapped_type = long long int; key_type = std::__cxx11::basic_string<char>]'
  524 |       operator[](key_type&& __k)
      |       ^~~~~~~~
/usr/include/c++/14/bits/stl_map.h:524:29: note:   no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<char>, char>::value_type' {aka 'char'} to 'std::map<std::__cxx11::basic_string<char>, long long int>::key_type&&' {aka 'std::__cxx11::basic_string<char>&&'}
  524 |       operator[](key_type&& __k)
      |                  ~~~~~~~~~~~^~~
a.cc:15:27: error: cannot convert 'std::map<std::__cxx11::basic_string<char>, long long int>::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, long long int>, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, long long int> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, long long int> > >::iterator'} to 'll' {aka 'long long int'} in initialization
   15 |         for(ll itr=a.begin();itr!=a.end();itr++){
      |                    ~~~~~~~^~
      |                           |
      |                           std::map<std::__cxx11::basic_string<char>, long long int>::iterator {aka std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, long long int>, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, long long int> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, long long int> > >::iterator}
a.cc:15:33: error: no match for 'operator!=' (operand types are 'll' {aka 'long long int'} and 'std::map<std::__cxx11::basic_string<char>, long long int>::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, long long int>, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, long long int> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, long long int> > >::iterator'})
   15 |         for(ll itr=a.begin();itr!=a.end();itr++){
      |                              ~~~^~~~~~~~~
      |                              |         |
      |                              |         std::map<std::__cxx11::basic_string<char>, long long int>::iterator {aka std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, long long int>, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, long long int> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, long long int> > >::iterator}
      |                              ll {aka long long int}
In file included from /usr/include/c++/14/regex:68,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:181:
/usr/include/c++/14/bits/regex.h:1132:5: note: candidate: 'template<class _BiIter> bool std::__cxx11::operator!=(const sub_match<_BiIter>&, const sub_match<_BiIter>&)'
 1132 |     operator!=(const sub_match<_BiIter>& __lhs, const sub_match<_BiIter>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1132:5: note:   template argument deduction/substitution failed:
a.cc:15:41: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'll' {aka 'long long int'}
   15 |         for(ll itr=a.begin();itr!=a.end();itr++){
      |                                         ^
/usr/include/c++/14/bits/regex.h:1212:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator!=(__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&, const sub_match<_BiIter>&)'
 1212 |     operator!=(const __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1212:5: note:   template argument deduction/substitution failed:
a.cc:15:41: note:   mismatched types 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>' and 'll' {aka 'long long int'}
   15 |         for(ll itr=a.begin();itr!=a.end();itr++){
      |                                         ^
/usr/include/c++/14/bits/regex.h:1305:5: note: candidate: 'template<class _Bi_iter, class _Ch_traits, class _Ch_alloc> bool std::__cxx11::operator!=(const sub_match<_BiIter>&, __sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>&)'
 1305 |     operator!=(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1305:5: note:   template argument deduction/substitution failed:
a.cc:15:41: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'll' {aka 'long long int'}
   15 |         for(ll itr=a.begin();itr!=a.end();itr++){
      |                                         ^
/usr/include/c++/14/bits/regex.h:1379:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator!=(const typename std::iterator_traits<_Iter>::value_type*, const sub_match<_BiIter>&)'
 1379 |     operator!=(typename iterator_traits<_Bi_iter>::value_type const* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1379:5: note:   template argument deduction/substitution failed:
a.cc:15:41: note:   'std::map<std::__cxx11::basic_string<char>, long long int>::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, long long int>, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, long long int> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, long long int> > >::iterator'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   15 |         for(ll itr=a.begin();itr!=a.end();itr++){
      |                                         ^
/usr/include/c++/14/bits/regex.h:1473:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator!=(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type*)'
 1473 |     operator!=(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1473:5: note:   template argument deduction/substitution failed:
a.cc:15:41: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'll' {aka 'long long int'}
   15 |         for(ll itr=a.begin();itr!=a.end();itr++){
      |                                         ^
/usr/include/c++/14/bits/regex.h:1547:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator!=(const typename std::iterator_traits<_Iter>::value_type&, const sub_match<_BiIter>&)'
 1547 |     operator!=(typename iterator_traits<_Bi_iter>::value_type const& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1547:5: note:   template argument deduction/substitution failed:
a.cc:15:41: note:   'std::map<std::__cxx11::basic_string<char>, long long int>::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, long long int>, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, long long int> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, long long int> > >::iterator'} is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   15 |         for(ll itr=a.begin();itr!=a.end();itr++){
      |                                         ^
/usr/include/c++/14/bits/regex.h:1647:5: note: candidate: 'template<class _Bi_iter> bool std::__cxx11::operator!=(const sub_match<_BiIter>&, const typename std::iterator_traits<_Iter>::value_type&)'
 1647 |     operator!=(const sub_match<_Bi_iter>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:1647:5: note:   template argument deduction/substitution failed:
a.cc:15:41: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'll' {aka 'long long int'}
   15 |         for(ll itr=a.begin();itr!=a.end();itr++){
      |                                         ^
/usr/include/c++/14/bits/regex.h:2213:5: note: candidate: 'template<class _Bi_iter, class _Alloc> bool std::__cxx11::operator!=(const match_results<_BiIter, _Alloc>&, const match_results<_BiIter, _Alloc>&)'
 2213 |     operator!=(const match_results<_Bi_iter, _Alloc>& __m1,
      |     ^~~~~~~~
/usr/include/c++/14/bits/regex.h:2213:5: note:   template argument deduction/substitution failed:
a.cc:15:41: note:   mismatched types 'const std::__cxx11::matc