HDU 1509

 Windows Message Queue

Time Limit:1000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u

Description

Message queue is the basic fundamental of windows system. For each process, the system maintains a message queue. If something happens to this process, such as mouse click, text change, the system will add a message to the queue. Meanwhile, the process will do a loop for getting message from the queue according to the priority value if it is not empty. Note that the less priority value means the higher priority. In this problem, you are asked to simulate the message queue for putting messages to and getting message from the message queue.

Input

There's only one test case in the input. Each line is a command, "GET" or "PUT", which means getting message or putting message. If the command is "PUT", there're one string means the message name and two integer means the parameter and priority followed by. There will be at most 60000 command. Note that one message can appear twice or more and if two messages have the same priority, the one comes first will be processed first.(i.e., FIFO for the same priority.) Process to the end-of-file.

Output

For each "GET" command, output the command getting from the message queue with the name and parameter in one line. If there's no message in the queue, output "EMPTY QUEUE!". There's no output for "PUT" command.

Sample Input

GET
PUT msg1 10 5
PUT msg2 10 4
GET
GET
GET

Sample Output

EMPTY QUEUE!
msg2 10
msg1 10
EMPTY QUEUE!

一.题意分析

输入多组数据，如果输入GET，就输出队列顶部元素，如果输入PUT，那么依次输入元素的名字，优先级，数值。在队列内部，排列顺序按照优先级排序，其中如果参数数值越大，那么优先级越低，反之越小。

二.思路过程

优先级队列

按照输入输出入队出队

三.代码

#include <iostream>
#include <cstdio>
#include <queue>
#include <string.h>
using namespace std;

struct node
{
    char name[10];
    int canshu;
    int priority;
    int num;
    bool operator < (const node &b) const
    {
        if(priority == b.priority)
            return num>b.num;
        return priority>b.priority;
    }
};

int main()
{
    int tot = 0;
    char str[20];
    priority_queue<node>Q;

    while(scanf("%s", str)!=EOF)
    {
        if(strcmp(str, "GET")==0)
        {
            if(!Q.empty())
            {
                printf("%s %d\n", Q.top().name, Q.top().canshu);
                Q.pop();
            }
            else
                printf("EMPTY QUEUE!\n");
        }
        else
        {
            node temp;
            scanf("%s%d%d", &temp.name, &temp.canshu, &temp.priority);
            temp.num=++tot;
            Q.push(temp);
        }
    }
    return 0;
}
/*
GET
PUT msg1 10 5
PUT msg2 10 4
GET
GET
GET
*/