Windows Message Queue--hdu1509

Windows Message Queue

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 4395 Accepted Submission(s): 1745

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!

这个题的大意是：输入GET就输出输入的数据，如果没数据就输出EMPTY QUEUE!

每个数据都有优先级，优先级越小越先输出！优先级相同时，谁先输入谁就先输出！

分析：用优先级数列来做

 1 #include<stdio.h>
 2 #include<string.h>
 3 #include<algorithm>
 4 #include<queue>
 5 #define max 60010
 6 using namespace std;
 7 struct as
 8 {
 9     char a[80];
10     int b,c,d;
11     bool friend operator <(as x,as y)
12     {
13         if(x.c!=y.c)
14             return x.c>y.c;//如果优先级不相等，从小到大排 
15         else
16             return x.d>y.d;//如果优先级相等，按输入先后顺序排 
17      } 
18 }aa[max];
19 priority_queue<struct as>q;
20 char str[80];
21 int main()
22 {
23     int i=0,j,k,n;
24     while(scanf("%s",str)!=EOF)
25     {
26         getchar();
27         if(strcmp(str,"PUT")==0)
28         {
29             scanf("%s",aa[i].a);
30             scanf("%d %d",&aa[i].b,&aa[i].c);//输入参数和优先级 
31             aa[i].d=i;//记录输入的先后次序，以便aa[i].y相等时比较 
32             q.push(aa[i]);
33             i++;
34         }
35         else if(strcmp(str,"GET")==0)
36         {
37             if(q.empty())
38             printf("EMPTY QUEUE!
");
39             else
40             {
41                 struct as er=q.top();
42                 q.pop();
43                 printf("%s %d
",er.a,er.b);
44             }
45          } 
46     }
47     return 0;
48 }