HDU5349——multiset——MZL's simple problem

http://acm.hdu.edu.cn/showproblem.php?pid=5349

/************************************************
* Author        :Powatr
* Created Time  :2015-8-9 19:37:49
* File Name     :F.cpp
 ************************************************/

#include <cstdio>
#include <algorithm>
#include <iostream>
#include <sstream>
#include <cstring>
#include <cmath>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <bitset>
#include <cstdlib>
#include <ctime>
using namespace std;

#define lson l, mid, rt << 1
#define rson mid + 1, r, rt << 1 | 1
typedef long long ll;
const int MAXN = 1e5 + 10;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
multiset<int> S;
multiset<int> :: iterator it;
int main(){
    int n;
    int m, k;
    while(~scanf("%d", &n)){
        S.clear();
        while(n--){
            scanf("%d", &m);
            if(m == 1) {
                scanf("%d", &k);
                S.insert(k);
            }
            if(m == 2){
                if(S.empty()) continue;
                S.erase(S.begin());
            }
            else if(m == 3){
                if(S.empty()){
                    printf("0\n");
                    continue;
                }
                else{
                    it = S.end(); it--;
                    printf("%d\n", *it);
                }
            }
        }
    }
        return 0;
}