ZOJ-2724-Windows Message Queue

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

GETPUT msg1 10 5PUT msg2 10 4GETGETGET

Sample Output

EMPTY QUEUE!msg2 10msg1 10EMPTY QUEUE!

#include <iostream>#include <string>#include <queue>using namespace std;struct node{    string name;    int parameter;    int priority;};bool operator <(node n1,node n2){    if(n1.priority>n2.priority)        return true;    else        return false;}int main(){    priority_queue <node> message;    node temp;    string str;    while(cin>>str)    {        if(str=="GET"&&message.empty())            cout<<"EMPTY QUEUE!"<<endl;        else if(str=="GET"&&!message.empty())        {            cout<<message.top().name<<' '<<message.top().parameter<<endl;            message.pop();        }        else if(str=="PUT")        {            cin>>temp.name>>temp.parameter>>temp.priority;            message.push(temp);        }    }    return 0;}