P50709: Col·lecció de números

#include <iostream>
#include <queue>
using namespace std;

int main() {
  int n;
  char action;
  priority_queue<int> pq;
  while (cin >> action) {
    switch (action) {
      case 'S':
    cin >> n;
    pq.push(n);
    break;
      case 'A':
    if (pq.empty()) cout << "error!" << endl;
    else cout << pq.top() << endl;
    break;
      case 'R':
    if (pq.empty()) cout << "error!" << endl;
    else pq.pop();
    break;
      case 'I':
    if (pq.empty()) cout << "error!" << endl;
    else {
      int aux = pq.top();
      pq.pop();
      cin >> n;
      aux += n;
      pq.push(aux);
    }
    break;
      case 'D':
    if (pq.empty()) cout << "error!" << endl;
    else {
      int aux = pq.top();
      pq.pop();
      cin >> n;
      aux -= n;
      pq.push(aux);
    }
    break;
      default:
    break;
    }
  }
}

//JosepRivaille