hdu1509Windows Message Queue

Windows Message Queue

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 4053    Accepted Submission(s): 1593

Problem 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!
 
 
 
/*
题意：优先队列的简单应用，GET表示得到信息，PUT表示输入，输入时包括“信息名  参数  优先级”其中优先级越小则优先程度越高，
注意当优先级相同时则输出最早输入的那个，因此要用个n标记输入的顺序，刚开始置零，PUT一个就加加
若队列为空想GET的话则输出EMPTY QUEUE!不为空输出优先级（且最早输入的值）“信息名   参数值”
题解：定义Windows Message结构体（详细注释）
*/
 
#include<iostream>
#include<cstdio>
#include<queue>
using namespace std;
struct node
{
	char m[1001];//存message
	int num;	//存储输入顺序
	int c;		//参数
	int p;		//优先级
	bool operator < (const node a) const		//重载运算符，定义优先级
	{
		if(p==a.p)			//优先级相同，则按照输入顺序
			return num>a.num;
		return p>a.p;		//否则按照优先级排序，优先级低的先排
	}
}temp;		//temp表示输入缓存
priority_queue< node >q1;
int main()
{
	char s1[3];
	int n=0;
	while(scanf("%s",s1)!=EOF)
	{
		if(strcmp(s1,"GET")==0)
		{
			if(q1.empty())
				cout<<"EMPTY QUEUE!"<<endl;
			else
			{
				cout<<q1.top().m<<" "<<q1.top().c<<endl;
				q1.pop();
			}
		}
		else if(strcmp(s1,"PUT")==0)
		{
			n++;
			temp.num=n;
			scanf("%s%d%d",temp.m,&temp.c,&temp.p);
			q1.push(temp);
			
		}
	}
	return 0;
}