Language: C++

#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<algorithm>
#include<string>
#include<queue>
#include<stack>
#include<set>
#include<list>
#include<unordered_map>
#include<vector>

using namespace std;

#define rep(i,n) for(int i=0; i<n; i++)
#define ll long long

int main(){
    string S, T;
    cin>>S>>T;
    char cvt;
    unordered_map<char, char> m;
    rep(i, S.size()) {
        auto itr = m.find(S[i]);
        cout<<cvt<<endl;
        if (*itr != m.end()) {
            if (T[i] != m[S[i]]) {
                printf("No");
                return 0;
            }
        }
        else
            m[S[i]] = T[i];
    }
    cout<<"Yes"<<endl;

    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:26:18: error: no match for 'operator!=' (operand types are 'std::pair<const char, char>' and 'std::unordered_map<char, char>::iterator' {aka 'std::__detail::_Insert_base<char, std::pair<const char, char>, std::allocator<std::pair<const char, char> >, std::__detail::_Select1st, std::equal_to<char>, std::hash<char>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::iterator'})
   26 |         if (*itr != m.end()) {
      |             ~~~~ ^~ ~~~~~~~
      |             |            |
      |             |            std::unordered_map<char, char>::iterator {aka std::__detail::_Insert_base<char, std::pair<const char, char>, std::allocator<std::pair<const char, char> >, std::__detail::_Select1st, std::equal_to<char>, std::hash<char>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::iterator}
      |             std::pair<const char, char>
In file included from /usr/include/c++/14/iosfwd:42,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:3:
/usr/include/c++/14/bits/postypes.h:197:5: note: candidate: 'template<class _StateT> bool std::operator!=(const fpos<_StateT>&, const fpos<_StateT>&)'
  197 |     operator!=(const fpos<_StateT>& __lhs, const fpos<_StateT>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/postypes.h:197:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::pair<const char, char>' is not derived from 'const std::fpos<_StateT>'
   26 |         if (*itr != m.end()) {
      |                           ^
In file included from /usr/include/c++/14/string:43,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/bits/allocator.h:243:5: note: candidate: 'template<class _T1, class _T2> bool std::operator!=(const allocator<_CharT>&, const allocator<_T2>&)'
  243 |     operator!=(const allocator<_T1>&, const allocator<_T2>&)
      |     ^~~~~~~~
/usr/include/c++/14/bits/allocator.h:243:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::pair<const char, char>' is not derived from 'const std::allocator<_CharT>'
   26 |         if (*itr != m.end()) {
      |                           ^
In file included from /usr/include/c++/14/string:48:
/usr/include/c++/14/bits/stl_iterator.h:455:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_Iterator>&)'
  455 |     operator!=(const reverse_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:455:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::pair<const char, char>' is not derived from 'const std::reverse_iterator<_Iterator>'
   26 |         if (*itr != m.end()) {
      |                           ^
/usr/include/c++/14/bits/stl_iterator.h:500:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const reverse_iterator<_Iterator>&, const reverse_iterator<_IteratorR>&)'
  500 |     operator!=(const reverse_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:500:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::pair<const char, char>' is not derived from 'const std::reverse_iterator<_Iterator>'
   26 |         if (*itr != m.end()) {
      |                           ^
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note: candidate: 'template<class _IteratorL, class _IteratorR> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorR>&)'
 1686 |     operator!=(const move_iterator<_IteratorL>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1686:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::pair<const char, char>' is not derived from 'const std::move_iterator<_IteratorL>'
   26 |         if (*itr != m.end()) {
      |                           ^
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note: candidate: 'template<class _Iterator> constexpr bool std::operator!=(const move_iterator<_IteratorL>&, const move_iterator<_IteratorL>&)'
 1753 |     operator!=(const move_iterator<_Iterator>& __x,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1753:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::pair<const char, char>' is not derived from 'const std::move_iterator<_IteratorL>'
   26 |         if (*itr != m.end()) {
      |                           ^
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/string:51:
/usr/include/c++/14/bits/stl_pair.h:1052:5: note: candidate: 'template<class _T1, class _T2> constexpr bool std::operator!=(const pair<_T1, _T2>&, const pair<_T1, _T2>&)'
 1052 |     operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y)
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_pair.h:1052:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::unordered_map<char, char>::iterator' {aka 'std::__detail::_Insert_base<char, std::pair<const char, char>, std::allocator<std::pair<const char, char> >, std::__detail::_Select1st, std::equal_to<char>, std::hash<char>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::iterator'} is not derived from 'const std::pair<_T1, _T2>'
   26 |         if (*itr != m.end()) {
      |                           ^
In file included from /usr/include/c++/14/bits/basic_string.h:47,
                 from /usr/include/c++/14/string:54:
/usr/include/c++/14/string_view:651:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(basic_string_view<_CharT, _Traits>, basic_string_view<_CharT, _Traits>)'
  651 |     operator!=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:651:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::pair<const char, char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   26 |         if (*itr != m.end()) {
      |                           ^
/usr/include/c++/14/string_view:658:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(basic_string_view<_CharT, _Traits>, __type_identity_t<basic_string_view<_CharT, _Traits> >)'
  658 |     operator!=(basic_string_view<_CharT, _Traits> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:658:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::pair<const char, char>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   26 |         if (*itr != m.end()) {
      |                           ^
/usr/include/c++/14/string_view:666:5: note: candidate: 'template<class _CharT, class _Traits> constexpr bool std::operator!=(__type_identity_t<basic_string_view<_CharT, _Traits> >, basic_string_view<_CharT, _Traits>)'
  666 |     operator!=(__type_identity_t<basic_string_view<_CharT, _Traits>> __x,
      |     ^~~~~~~~
/usr/include/c++/14/string_view:666:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::__detail::_Node_iterator<std::pair<const char, char>, false, false>' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   26 |         if (*itr != m.end()) {
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3833:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3833 |     operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3833:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::pair<const char, char>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   26 |         if (*itr != m.end()) {
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3847:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3847 |     operator!=(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3847:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   mismatched types 'const _CharT*' and 'std::pair<const char, char>'
   26 |         if (*itr != m.end()) {
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3860:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> bool std::operator!=(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3860 |     operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3860:5: note:   template argument deduction/substitution failed:
a.cc:26:27: note:   'std::pair<const char, char>' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   26 |         if (*itr != m.end()) {
      |                           ^
In file included from /usr/include/c++/14/bits/memory_resource.h:47,
                 from /usr/include/c++/14/string:68:
/usr/include/c++/14/tuple:2613:5: note: candidate: 'template<class ... _TElements, class ... _UElements> constexpr bool std::operator!=(const tuple<_UTypes ...>&, const tuple<_Elements ...>&)'
 2613 |     operator!=(const tuple<_TElements...>& __t,
      |     ^~~~~~~~
/usr/include/c++/14/tuple:2613:5: note:   template argumen