Language: C++

#include <iostream>
#include <vector>
#include <utility>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <iomanip>
#include <map>
typedef long long ll;

using namespace std;

int main(void)
{
    map<string, int> m;

    int n;
    cin >> n;

    for (int i = 0; i < n; i++) {
        string s;
        cin >> s;

        m[s] += 1;
    }

    int max = 0;
    for (const int& x : m) {
        int a = x.second;
        if (a > max)
            max = a;
    }

    for (int i = m.begin(); i != m.end(); i++) {
        if (i->second == max)
            cout << i->first << endl;
    }

    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:28:25: error: invalid initialization of reference of type 'const int&' from expression of type 'std::pair<const std::__cxx11::basic_string<char>, int>'
   28 |     for (const int& x : m) {
      |                         ^
a.cc:29:19: error: request for member 'second' in 'x', which is of non-class type 'const int'
   29 |         int a = x.second;
      |                   ^~~~~~
a.cc:34:25: error: cannot convert 'std::map<std::__cxx11::basic_string<char>, int>::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, int>, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, int> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, int> > >::iterator'} to 'int' in initialization
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                  ~~~~~~~^~
      |                         |
      |                         std::map<std::__cxx11::basic_string<char>, int>::iterator {aka std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, int>, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, int> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, int> > >::iterator}
a.cc:34:31: error: no match for 'operator!=' (operand types are 'int' and 'std::map<std::__cxx11::basic_string<char>, int>::iterator' {aka 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, int>, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, int> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, int> > >::iterator'})
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                             ~ ^~ ~~~~~~~
      |                             |         |
      |                             int       std::map<std::__cxx11::basic_string<char>, int>::iterator {aka std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, int>, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, int> >, std::less<std::__cxx11::basic_string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, int> > >::iterator}
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:1:
/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:34:40: note:   mismatched types 'const std::fpos<_StateT>' and 'int'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
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:34:40: note:   mismatched types 'const std::allocator<_CharT>' and 'int'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
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:34:40: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'int'
   34 |     for (int i = m.begin(); i != m.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/include/c++/14/bits/stl_iterator.h:500:5: note:   template argument deduction/substitution failed:
a.cc:34:40: note:   mismatched types 'const std::reverse_iterator<_Iterator>' and 'int'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
/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:34:40: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'int'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
/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:34:40: note:   mismatched types 'const std::move_iterator<_IteratorL>' and 'int'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
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:34:40: note:   mismatched types 'const std::pair<_T1, _T2>' and 'int'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
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:34:40: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'int'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
/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:34:40: note:   mismatched types 'std::basic_string_view<_CharT, _Traits>' and 'int'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
/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:34:40: note:   'std::_Rb_tree_iterator<std::pair<const std::__cxx11::basic_string<char>, int> >' is not derived from 'std::basic_string_view<_CharT, _Traits>'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
/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:34:40: note:   mismatched types 'const std::__cxx11::basic_string<_CharT, _Traits, _Allocator>' and 'int'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
/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:34:40: note:   mismatched types 'const _CharT*' and 'int'
   34 |     for (int i = m.begin(); i != m.end(); i++) {
      |                                        ^
/usr/include/c++/14/bit