Language: C++

#include "bits/stdc++.h"

using namespace std;

#define int long long
#define ll long long
typedef pair<int, int> P;
#define mod 1000000007
#define INF (1LL<<60)

#define rep(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define YES cout << "YES" << endl
#define Yes cout << "Yes" << endl
#define NO cout << "NO" << endl
#define No cout << "No" << endl


signed main(){

	int N, K;
	cin >> N >> K;
	vector<int> t(N), d(N);
	rep(i, N) cin >> t[i] >> d[i];

	priority_queue<P> p1;
	rep(i, N) p1.push(P(d[i], t[i]));	// dが大きい順に取れる

	map<int, int> m;	// 選んだものの中でm[kind] = count

	priority_queue<int, vector<int>, greater<int>> p2;	// 選んだものから小さい順に捨てる用
	int ans = 0, sum = 0;

	// 大きい順にK個とって種類ごとに個数を数える
	rep(i, K){
		sum += p1.top().first;
		m[p1.top().second] ++;
		// 2個以上選ばれた種類のものは、捨てる候補としてp2に入れる
		if (m[p1.top().second] > 1){
			p2.push(p1.top().first);
		}
		p1.pop();
	}
	ans = sum + m.size()*m.size();

	while (p2.size()>0 ){
		// p2から1個捨てる
		sum -= p2.top(); p2.pop();
		//p1からbestを取り出し追加
		sum += p1.top().first;
		if (m.find(p1.top().second) == m.end())
			m[p1.top().second] ++;
		p1.pop();
		ans = max(ans, sum + m.size()*m.size());
	}

	cout << ans << endl;

	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:53:26: error: no matching function for call to 'max(long long int&, long long unsigned int)'
   53 |                 ans = max(ans, sum + m.size()*m.size());
      |                       ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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:53:26: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
   53 |                 ans = max(ans, sum + m.size()*m.size());
      |                       ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/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:53:26: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   53 |                 ans = max(ans, sum + m.size()*m.size());
      |                       ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~