Language: C++

#include <iostream>
#include <unordered_map>
#define li long int
using namespace std;

li gcd(li,li);

int main()
{
  li a,b;
  cin >> a >> b;
  unordered_map<li,bool> arr;
  
  li g = gcd(a,b);
  
  if(g == 1)
  {
    cout << g;
    return 0;
  }
  
  for(li i=1;i<=g;i++)
  {
    if(g%i==0)
    {
      arr[i] = false;
    }
  }
  
  auto i;
  for(i=arr.end();i!=arr.begin()+1;i--)
  {
    for(auto j=i-1;j!=arr.begin();j--)
    {
      if(i->first % j->first == 0)
      {
        arr[i] = true;
        break;
      }
    }
  }
  int count = 0;
  for(auto i=arr.begin();i!=arr.end();i++)
    if(arr[i] == false)
      count++;
  
  cout << count;
  return 0;
}

li gcd(li a,li b)
{
  if(b==1 || a==1)
    return 1;
  if(b==0)
    return a;
  return gcd(b,a%b);
}


Compiler output:
a.cc: In function 'int main()':
a.cc:30:3: error: declaration of 'auto i' has no initializer
   30 |   auto i;
      |   ^~~~
a.cc:31:33: error: no match for 'operator+' (operand types are 'std::unordered_map<long int, bool>::iterator' {aka 'std::__detail::_Insert_base<long int, std::pair<const long int, bool>, std::allocator<std::pair<const long int, bool> >, std::__detail::_Select1st, std::equal_to<long int>, std::hash<long int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::iterator'} and 'int')
   31 |   for(i=arr.end();i!=arr.begin()+1;i--)
      |                      ~~~~~~~~~~~^~
      |                               |  |
      |                               |  int
      |                               std::unordered_map<long int, bool>::iterator {aka std::__detail::_Insert_base<long int, std::pair<const long int, bool>, std::allocator<std::pair<const long int, bool> >, std::__detail::_Select1st, std::equal_to<long int>, std::hash<long int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::iterator}
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:31:34: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'int'
   31 |   for(i=arr.end();i!=arr.begin()+1;i--)
      |                                  ^
/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:31:34: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'int'
   31 |   for(i=arr.end();i!=arr.begin()+1;i--)
      |                                  ^
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:31:34: note:   'std::unordered_map<long int, bool>::iterator' {aka 'std::__detail::_Insert_base<long int, std::pair<const long int, bool>, std::allocator<std::pair<const long int, bool> >, std::__detail::_Select1st, std::equal_to<long int>, std::hash<long int>, 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::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   31 |   for(i=arr.end();i!=arr.begin()+1;i--)
      |                                  ^
/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:31:34: note:   mismatched types 'const _CharT*' and 'std::__detail::_Node_iterator<std::pair<const long int, bool>, false, false>'
   31 |   for(i=arr.end();i!=arr.begin()+1;i--)
      |                                  ^
/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:31:34: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   31 |   for(i=arr.end();i!=arr.begin()+1;i--)
      |                                  ^
/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:31:34: note:   'std::unordered_map<long int, bool>::iterator' {aka 'std::__detail::_Insert_base<long int, std::pair<const long int, bool>, std::allocator<std::pair<const long int, bool> >, std::__detail::_Select1st, std::equal_to<long int>, std::hash<long int>, 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::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   31 |   for(i=arr.end();i!=arr.begin()+1;i--)
      |                                  ^
/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:31:34: note:   'std::unordered_map<long int, bool>::iterator' {aka 'std::__detail::_Insert_base<long int, std::pair<const long int, bool>, std::allocator<std::pair<const long int, bool> >, std::__detail::_Select1st, std::equal_to<long int>, std::hash<long int>, 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::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   31 |   for(i=arr.end();i!=arr.begin()+1;i--)
      |                                  ^
/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:31:34: note:   'std::unordered_map<long int, bool>::iterator' {aka 'std::__detail::_Insert_base<long int, std::pair<const long int, bool>, std::allocator<std::pair<const long int, bool> >, std::__detail::_Select1st, std::equal_to<long int>, std::hash<long int>, 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 'std::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   31 |   for(i=arr.end();i!=arr.begin()+1;i--)
      |                                  ^
/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:31:34: note:   'std::unordered_map<long int, bool>::iterator' {aka 'std::__detail::_Insert_base<long int, std::pair<const long int, bool>, std::allocator<std::pair<const long int, bool> >, std::__detail::_Select1st, std::equal_to<long int>, std::hash<long int>, 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::__cxx11::basic_string<_CharT, _Traits, _Allocator>'
   31 |   for(i=arr.end();i!=arr.begin()+1;i--)
      |                                  ^
/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 ar