HDU 1873 看病要排队 —— priority_queue 的使用

#include<queue>
#include<iostream>
#include<string>
#include<iomanip>
using namespace std;
struct person {
    int id, num;//编号，优先级
};
//先定义结构体，再写重载函数定义优先级比较简单明了 
bool operator < (const person &a, const person &b) {//重载 "<" 操作符定义优先级
    if (a.num == b.num)//当级别相同时从小到大排序 
        return a.id > b.id;
    else
        return a.num < b.num;//当级别不同是从大到小排序 
}
int main() {
    int n;
    while (cin >> n) {
        priority_queue<person>doctors[4];
        int id = 1, docIndex, num;
        string str;
        person temPer;
        while (n--) {
            cin >> str >> docIndex;
            if (str == "IN") {
                cin >> temPer.num;
                temPer.id = id++;//储存病人的编号
                doctors[docIndex].push(temPer);//把病人入相应医生队列
            }
            else {
                if (!doctors[docIndex].empty()) {//有病人在诊断 
                    temPer = doctors[docIndex].top();
                    doctors[docIndex].pop();
                    cout << temPer.id << endl;
                }
                else
                    cout << "EMPTY" << endl;
            }
        }
    }
}