Language: C++

#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

#define REP(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define all(x) (x).begin(),(x).end()
#define m0(x) memset(x,0,sizeof(x))

int dx4[4] = {1,0,-1,0}, dy4[4] = {0,1,0,-1};

int main(){
    ll k,n,ans=0,osum=0;
    cin>>n>>k;
    vector<pll> v(n);   //oishisa, neta
    priority_queue<pll> pqall;
    priority_queue<pll, vector<pll>, greater<pll>> pqkaburi;
    unordered_set<ll> us;
    for(int i = 0; i < n; i++)
    {
        ll t,d;
        cin>>t>>d;
        v[i]=make_pair(d,t);
        pqall.push(v[i]);
    }
    for(int i = 0; i < k; i++)
    {
        pll top = pqall.top();
        pqall.pop();
        if(us.find(top.second)==us.end())
        {
            us.insert(top.second);
            osum+=top.first;
        }
        else
        {
            pqkaburi.push(top);
            osum+=top.first;
        }
    }

    ans=max(ans,osum+us.size()*us.size());
    while(us.size()<k && pqall.size()>0){
        pll top = pqall.top();
        pqall.pop();
        if(us.find(top.second)==us.end())
        {
            us.insert(top.second);
            osum+=top.first;
            pll del = pqkaburi.top();
            pqkaburi.pop();
            osum-=del.first;
            ans=max(ans,osum+us.size()*us.size());
        }
    }
    
    cout<<ans<<endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:45:12: error: no matching function for call to 'max(ll&, long long unsigned int)'
   45 |     ans=max(ans,osum+us.size()*us.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:45:12: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
   45 |     ans=max(ans,osum+us.size()*us.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:45:12: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   45 |     ans=max(ans,osum+us.size()*us.size());
      |         ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:56:20: error: no matching function for call to 'max(ll&, long long unsigned int)'
   56 |             ans=max(ans,osum+us.size()*us.size());
      |                 ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/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:56:20: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'long long unsigned int')
   56 |             ans=max(ans,osum+us.size()*us.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
/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:56:20: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   56 |             ans=max(ans,osum+us.size()*us.size());
      |                 ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~