Language: C++

#include <bits/stdc++.h>
#include<vector>
using namespace std;
#define rep(i, n)        for(int i=0; i<(int)(n); ++i)
int main() {
  long long int a,c=0;cin>>a;
  string d;
  map<string,long long int>b;
  rep(i,a){
    cin>>d;
    sort(d.begin(),d.end());
    if(b.count(d))b[d]++;
    else b[d]=1;
  }
  for(auto i=b.begin();i!=b.end;i++){
    c+=b[i]*(b[i]+1)/2;
  }
  cout<<c;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:15:25: error: no match for 'operator!=' (operand types are 'std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, long long int> >' and '<unresolved overloaded function type>')
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                        ~^~~~~~~
      |                        |    |
      |                        |    <unresolved overloaded function type>
      |                        std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, 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,
                 from a.cc:1:
/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:15:29: note:   'std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, long long int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                             ^~~
/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:15:29: note:   'std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, long long int> >' is not derived from 'std::__cxx11::__sub_match_string<_Bi_iter, _Ch_traits, _Ch_alloc>'
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                             ^~~
/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:15:29: note:   'std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, long long int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                             ^~~
/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:15:29: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'std::map<std::__cxx11::basic_string<char>, long long int>::const_iterator (std::map<std::__cxx11::basic_string<char>, long long int>::*)() const noexcept' {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> > >::const_iterator (std::map<std::__cxx11::basic_string<char>, long long int>::*)() const noexcept'}
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                             ^~~
a.cc:15:29: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'std::map<std::__cxx11::basic_string<char>, long long int>::iterator (std::map<std::__cxx11::basic_string<char>, long long int>::*)() noexcept' {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 (std::map<std::__cxx11::basic_string<char>, long long int>::*)() noexcept'}
a.cc:15:29: note:   couldn't deduce template parameter '_Bi_iter'
/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:15:29: note:   'std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, long long int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                             ^~~
/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:15:29: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'std::map<std::__cxx11::basic_string<char>, long long int>::const_iterator (std::map<std::__cxx11::basic_string<char>, long long int>::*)() const noexcept' {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> > >::const_iterator (std::map<std::__cxx11::basic_string<char>, long long int>::*)() const noexcept'}
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                             ^~~
a.cc:15:29: note:   mismatched types 'const std::__cxx11::sub_match<_BiIter>' and 'std::map<std::__cxx11::basic_string<char>, long long int>::iterator (std::map<std::__cxx11::basic_string<char>, long long int>::*)() noexcept' {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 (std::map<std::__cxx11::basic_string<char>, long long int>::*)() noexcept'}
a.cc:15:29: note:   couldn't deduce template parameter '_Bi_iter'
/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:15:29: note:   'std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, long long int> >' is not derived from 'const std::__cxx11::sub_match<_BiIter>'
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                             ^~~
/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:15:29: note:   'std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, long long int> >' is not derived from 'const std::__cxx11::match_results<_BiIter, _Alloc>'
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                             ^~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:64,
                 from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h: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:15:29: note:   'std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, long long int> >' is not derived from 'const std::pair<_T1, _T2>'
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                             ^~~
In file included from /usr/include/c++/14/bits/stl_algobase.h:67:
/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:15:29: note:   'std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, long long int> >' is not derived from 'const std::reverse_iterator<_Iterator>'
   15 |   for(auto i=b.begin();i!=b.end;i++){
      |                             ^~~
/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/in