Windows Message Queue

Posted 2020-08-29 勿忘初心0924

Windows Message Queue

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)

Total Submission(s): 85 Accepted Submission(s): 53

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!

Author ZHOU, Ran

Source Zhejiang University Local Contest 2006, Preliminary

Recommend linle

/*
题意：简单的模拟两个操作：GET获取优先级最高的，PUT压进栈东西

初步思路：优先队列，搞一下，本来想偷一下懒。把以前写的代码贴上，结果死活不对。
*/
#include<bits/stdc++.h>
using namespace std;
struct node{
    string name;
    int val;
    int Rank;
    int time;
    node(){}
    node(string a,int b,int c,int d){
        name=a;
        val=b;
        Rank=c;
        time=d;
    }
    bool operator < (const node &other) const{
        if(Rank==other.Rank)
            return time>other.time;
        return Rank>other.Rank;
    }
};
priority_queue<node> Message;
string op;
string name;
int times=0;
int val,Rank;
void init(){
    times=0;
    while(!Message.empty()) Message.pop();
}
int main(){
    // freopen("in.txt","r",stdin);
    init();
    while(cin>>op){
        if(op=="GET"){
            if(Message.empty()) puts("EMPTY QUEUE!");
            else{
                cout<<Message.top().name<<" "<<Message.top().val<<endl;
                Message.pop();
            }
        }else{
            cin>>name>>val>>Rank;
            Message.push(node(name,val,Rank,times++));
        }
    }    
    return 0;
}