Problem p03148 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

using namespace std;
using ll = long long;

#define REP(i, n) for (long long i = 0; i < (n); i++)
#define FOR(i, m, n) for (long long i = (m); i < (n); ++i)
#define ALL(obj) (obj).begin(), (obj).end()

template <class T> using V = vector<T>;
template <class T, class U> using P = pair<T, U>;

const ll MOD = (ll)1e9 + 7;
const ll HINF = (ll)1e18;
const ll LINF = (ll)1e9;
const long double PI = 3.1415926535897932384626433;

template <class T> void corner(bool flg, T hoge) {
  if (flg) {
    cout << hoge << endl;
    exit(0);
  }
}
template <class T, class U>
ostream &operator<<(ostream &o, const map<T, U> &obj) {
  o << "{";
  for (auto &x : obj)
    o << " {" << x.first << " : " << x.second << "}"
      << ",";
  o << " }";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const set<T> &obj) {
  o << "{";
  for (auto itr = obj.begin(); itr != obj.end(); ++itr)
    o << (itr != obj.begin() ? ", " : "") << *itr;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const vector<T> &obj) {
  o << "{";
  for (int i = 0; i < (int)obj.size(); ++i)
    o << (i > 0 ? ", " : "") << obj[i];
  o << "}";
  return o;
}
template <class T, class U>
ostream &operator<<(ostream &o, const pair<T, U> &obj) {
  o << "{" << obj.first << ", " << obj.second << "}";
  return o;
}
template <template <class tmp> class T, class U>
ostream &operator<<(ostream &o, const T<U> &obj) {
  o << "{";
  for (auto itr = obj.begin(); itr != obj.end(); ++itr)
    o << (itr != obj.begin() ? ", " : "") << *itr;
  o << "}";
  return o;
}
void print(void) { cout << endl; }
template <class Head> void print(Head &&head) {
  cout << head;
  print();
}
template <class Head, class... Tail> void print(Head &&head, Tail &&...tail) {
  cout << head << " ";
  print(forward<Tail>(tail)...);
}
template <class T> void chmax(T &a, const T b) { a = max<T>(a, b); }
template <class T> void chmin(T &a, const T b) { a = min<T>(a, b); }
void YN(bool flg) { cout << ((flg) ? "YES" : "NO") << endl; }
void Yn(bool flg) { cout << ((flg) ? "Yes" : "No") << endl; }
void yn(bool flg) { cout << ((flg) ? "yes" : "no") << endl; }

int main() {
  ll N, K;
  cin >> N >> K;
  V<P<ll, ll>> dt;
  REP(i, N) {
    ll t, d;
    cin >> t >> d;
    dt.push_back({d, t});
  }
  sort(ALL(dt), greater<P<ll, ll>>());

  ll ans = 0, sum = 0;
  priority_queue<ll, V<ll>, greater<ll>> pq;
  map<ll, ll> mp;
  REP(i, K) {
    if (mp[dt[i].second] == 0) {
      mp[dt[i].second]++;
      sum += dt[i].first;
    } else {
      pq.push(dt[i].first);
      sum += dt[i].first;
    }
  }
  chmax(ans, sum + (ll)mp.size() * (ll)mp.size());
  FOR(i, K, N) {
    if (mp[dt[i].second] == 0) {
      mp[dt[i].second]++;
      sum += dt[i].first;
      sum -= pq.top();
      pq.pop();
    }
    chmax(ans, sum + (ll)mp.size() * (ll)mp.size());
  }
  cout << ans << endl;

  return 0;
}


Fixed submission:
#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

using namespace std;
using ll = long long;

#define REP(i, n) for (long long i = 0; i < (n); i++)
#define FOR(i, m, n) for (long long i = (m); i < (n); ++i)
#define ALL(obj) (obj).begin(), (obj).end()

template <class T> using V = vector<T>;
template <class T, class U> using P = pair<T, U>;

const ll MOD = (ll)1e9 + 7;
const ll HINF = (ll)1e18;
const ll LINF = (ll)1e9;
const long double PI = 3.1415926535897932384626433;

template <class T> void corner(bool flg, T hoge) {
  if (flg) {
    cout << hoge << endl;
    exit(0);
  }
}
template <class T, class U>
ostream &operator<<(ostream &o, const map<T, U> &obj) {
  o << "{";
  for (auto &x : obj)
    o << " {" << x.first << " : " << x.second << "}"
      << ",";
  o << " }";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const set<T> &obj) {
  o << "{";
  for (auto itr = obj.begin(); itr != obj.end(); ++itr)
    o << (itr != obj.begin() ? ", " : "") << *itr;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const vector<T> &obj) {
  o << "{";
  for (int i = 0; i < (int)obj.size(); ++i)
    o << (i > 0 ? ", " : "") << obj[i];
  o << "}";
  return o;
}
template <class T, class U>
ostream &operator<<(ostream &o, const pair<T, U> &obj) {
  o << "{" << obj.first << ", " << obj.second << "}";
  return o;
}
template <template <class tmp> class T, class U>
ostream &operator<<(ostream &o, const T<U> &obj) {
  o << "{";
  for (auto itr = obj.begin(); itr != obj.end(); ++itr)
    o << (itr != obj.begin() ? ", " : "") << *itr;
  o << "}";
  return o;
}
void print(void) { cout << endl; }
template <class Head> void print(Head &&head) {
  cout << head;
  print();
}
template <class Head, class... Tail> void print(Head &&head, Tail &&...tail) {
  cout << head << " ";
  print(forward<Tail>(tail)...);
}
template <class T> void chmax(T &a, const T b) { a = max<T>(a, b); }
template <class T> void chmin(T &a, const T b) { a = min<T>(a, b); }
void YN(bool flg) { cout << ((flg) ? "YES" : "NO") << endl; }
void Yn(bool flg) { cout << ((flg) ? "Yes" : "No") << endl; }
void yn(bool flg) { cout << ((flg) ? "yes" : "no") << endl; }

int main() {
  ll N, K;
  cin >> N >> K;
  V<P<ll, ll>> dt;
  REP(i, N) {
    ll t, d;
    cin >> t >> d;
    dt.push_back({d, t});
  }
  sort(ALL(dt), greater<P<ll, ll>>());

  ll ans = 0, sum = 0;
  priority_queue<ll, V<ll>, greater<ll>> pq;
  map<ll, ll> mp;
  REP(i, K) {
    if (mp[dt[i].second] == 0) {
      mp[dt[i].second]++;
      sum += dt[i].first;
    } else {
      pq.push(dt[i].first);
      sum += dt[i].first;
    }
  }
  chmax(ans, sum + (ll)mp.size() * (ll)mp.size());
  FOR(i, K, N) {
    if (pq.size() && mp[dt[i].second] == 0) {
      mp[dt[i].second]++;
      sum += dt[i].first;
      sum -= pq.top();
      pq.pop();
    }
    chmax(ans, sum + (ll)mp.size() * (ll)mp.size());
  }
  cout << ans << endl;

  return 0;
}