Language: C++

#include <iostream>
#include <string>
#include <map>

using namespace std;

int main(){
    string str;
    cin >> str;
    map<char,int> data;
    for(int i=0;i<str.length();i++){
        data[str[i]]++;
    }
    int res=0;
    for(auto itr=data.begin();itr!=data.end();itr++){
        for(auto itr1=itr+1;itr1!=data.end();itr1++){
            if(itr==itr1){
                continue;
            }
            res+=(itr->second)*(itr1->second);
        }
    }
    cout << res/2+1 << endl;
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:16:26: error: no match for 'operator+' (operand types are 'std::_Rb_tree_iterator<std::pair<const char, int> >' and 'int')
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                       ~~~^~
      |                       |   |
      |                       |   int
      |                       std::_Rb_tree_iterator<std::pair<const char, int> >
In file included from /usr/include/c++/14/string:48,
                 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,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_iterator.h:627:5: note: candidate: 'template<class _Iterator> constexpr std::reverse_iterator<_Iterator> std::operator+(typename reverse_iterator<_Iterator>::difference_type, const reverse_iterator<_Iterator>&)'
  627 |     operator+(typename reverse_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:627:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'int'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/stl_iterator.h:1798:5: note: candidate: 'template<class _Iterator> constexpr std::move_iterator<_IteratorL> std::operator+(typename move_iterator<_IteratorL>::difference_type, const move_iterator<_IteratorL>&)'
 1798 |     operator+(typename move_iterator<_Iterator>::difference_type __n,
      |     ^~~~~~~~
/usr/include/c++/14/bits/stl_iterator.h:1798:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'int'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
In file included from /usr/include/c++/14/string:54:
/usr/include/c++/14/bits/basic_string.h:3598:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3598 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3598:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   'std::_Rb_tree_iterator<std::pair<const char, int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3616:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3616 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3616:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   mismatched types 'const _CharT*' and 'std::_Rb_tree_iterator<std::pair<const char, int> >'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3635:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3635 |     operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Alloc>& __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3635:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3652:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, const _CharT*)'
 3652 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3652:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   'std::_Rb_tree_iterator<std::pair<const char, int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3670:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, _CharT)'
 3670 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3670:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   'std::_Rb_tree_iterator<std::pair<const char, int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3682:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const __cxx11::basic_string<_CharT, _Traits, _Allocator>&)'
 3682 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3682:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   'std::_Rb_tree_iterator<std::pair<const char, int> >' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3689:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const __cxx11::basic_string<_CharT, _Traits, _Allocator>&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3689 |     operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3689:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   'std::_Rb_tree_iterator<std::pair<const char, int> >' is not derived from 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3696:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3696 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3696:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   'std::_Rb_tree_iterator<std::pair<const char, int> >' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3719:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(const _CharT*, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3719 |     operator+(const _CharT* __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3719:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   mismatched types 'const _CharT*' and 'std::_Rb_tree_iterator<std::pair<const char, int> >'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3726:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(_CharT, __cxx11::basic_string<_CharT, _Traits, _Allocator>&&)'
 3726 |     operator+(_CharT __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3726:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   mismatched types 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3733:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, const _CharT*)'
 3733 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3733:5: note:   template argument deduction/substitution failed:
a.cc:16:27: note:   'std::_Rb_tree_iterator<std::pair<const char, int> >' is not derived from 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   16 |         for(auto itr1=itr+1;itr1!=data.end();itr1++){
      |                           ^
/usr/include/c++/14/bits/basic_string.h:3740:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::__cxx11::basic_string<_CharT, _Traits, _Allocator> std::operator+(__cxx11::basic_string<_CharT, _Traits, _Allocator>&&, _CharT)'
 3740 |     operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
      |     ^~~~~~~~
/usr/include/c++/14/bits/basic_string.h:3740:5: note:   template