Language: C++

#include <bits/stdc++.h>
#define REP(i,n) for(int i=0;i<n;i++)
using namespace std;
 
int main(){
  int n,k;
  cin>>n>>k;
  map<int,int> mp;
  int a;
  REP(i,n){
    cin>>a;
    mp[a]++;
  }
  vector<pair<int,int>> cnts;
  int num,cnt;
  for(auto p:mp){
    num = p.first;
    cnt = p.second;
    cnts.push_back(make_pair(cnt,num));
  }
  
  sort(cnt.begin(),cnts.end());
  int ans=0;
  REP(i,max(0,cnts.size()-k)){
    ans += cnts.first();
  }
  cout<<ans<<endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:22:12: error: request for member 'begin' in 'cnt', which is of non-class type 'int'
   22 |   sort(cnt.begin(),cnts.end());
      |            ^~~~~
a.cc:24:12: error: no matching function for call to 'max(int, std::vector<std::pair<int, int> >::size_type)'
   24 |   REP(i,max(0,cnts.size()-k)){
      |         ~~~^~~~~~~~~~~~~~~~~
a.cc:2:32: note: in definition of macro 'REP'
    2 | #define REP(i,n) for(int i=0;i<n;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:24:12: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'})
   24 |   REP(i,max(0,cnts.size()-k)){
      |         ~~~^~~~~~~~~~~~~~~~~
a.cc:2:32: note: in definition of macro 'REP'
    2 | #define REP(i,n) for(int i=0;i<n;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:24:12: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   24 |   REP(i,max(0,cnts.size()-k)){
      |         ~~~^~~~~~~~~~~~~~~~~
a.cc:2:32: note: in definition of macro 'REP'
    2 | #define REP(i,n) for(int i=0;i<n;i++)
      |                                ^
a.cc:25:17: error: 'class std::vector<std::pair<int, int> >' has no member named 'first'
   25 |     ans += cnts.first();
      |                 ^~~~~