Language: C++

#include <bits/stdc++.h>
typedef long long int lli;
using namespace std;

int main()
{
	ios_base::sync_with_stdio(0);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int n,i,m=0;
    cin>>n;
    vector <string> a,b,c;
    string x;
    for(i=0;i<n;++i)
    {
        cin>>x;
        if(find(a.begin(),a.end(),x)==a.end())
            a.push_back(x);
        else
        {
            if(find(b.begin(),b.end(),x)==b.end())
                c.push_back(x);
            b.push_back(x);
        }
    }
    if(b.size()==0)
        b=c=a;
    for(i=0;i<c.size();++i)
    {
        m=max(m,count(b.begin(),b.end(),c[i]));
    }
    a.clear();
    for(i=0;i<c.size();++i)
    {
        if(count(b.begin(),b.end(),c[i])==m)
            a.push_back(c[i]);
    }
    sort(a.begin(),a.end());
    for(auto it:a)
        cout<<it<<"\n";
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:30:14: error: no matching function for call to 'max(int&, std::__iterator_traits<__gnu_cxx::__normal_iterator<std::__cxx11::basic_string<char>*, std::vector<std::__cxx11::basic_string<char> > >, void>::difference_type)'
   30 |         m=max(m,count(b.begin(),b.end(),c[i]));
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:30:14: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'std::__iterator_traits<__gnu_cxx::__normal_iterator<std::__cxx11::basic_string<char>*, std::vector<std::__cxx11::basic_string<char> > >, void>::difference_type' {aka 'long int'})
   30 |         m=max(m,count(b.begin(),b.end(),c[i]));
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:30:14: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   30 |         m=max(m,count(b.begin(),b.end(),c[i]));
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~