Topic Links:
http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=2724
Title 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 would add a message to the queue. Meanwhile, the process would do a loop for getting message from the queue according to the priority value if it's not empt Y. Note the less priority value means the higher priority. In this problem, you is 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 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 both integer means the parameter and priority Follo Wed by. There'll is at the most 60000 command. Note that one message can appear twice or more and if the messages has the same priority, the one comes first would be pro Cessed first. (i.e., FIFO for the same priority.) Process to the End-of-file.
Output
For each "GET" command, the output of the command getting from the message queue with the name and parameter on one line. If There's no message in the queue, output "EMPTY queue!". There ' s no output for "PUT" command.
Sample Input
Getput MSG1 5PUT msg2 4GETGETGET
Sample Output
EMPTY queue!msg2 10MSG1 10EMPTY queue!
1 /*problem Impersonation Message Queuing, for each put command, inserts subsequent commands and parameters into the queue by priority2 for each get command, output the name and parameters of the message at the top of the queue, if the output of the queuing space is empty queue!3 when inserting the attention by priority, if the priority is the same, in order to queue in sequence. 4 solving ideas using the priority queue in C++stl. Recognition operation, get output team first or empty queue!,put into priority queue, define structure comparison rule*/5#include <cstdio>6#include <queue>7#include <cstring>8 using namespacestd;9 Ten structinfo{ One Charname[ -]; A intpara; - intrank; - BOOL operator< (ConstInfo &a)Const{ the returnA.rank < rank;//returns 0 when equals. - } - }; - + intMain () - { + Charop[5]; APriority_queue<info>PQ; at Info temp; - while(SCANF ("%s", op)! =EOF) { - if(strcmp (OP,"GET") ==0) - { - if(Pq.empty ())//Empty - { inprintf"EMPTY queue!\n"); - } to Else//Non-empty + { -printf"%s%d\n", Pq.top (). Name,pq.top (). para); the Pq.pop (); * } $ }Panax Notoginseng if(strcmp (OP,"PUT") ==0) - { thescanf"%s%d%d",temp.name,&temp.para,&Temp.rank); + Pq.push (temp); A } the } +}
Zoj 2724 Windows Message Queue (using Priority_queue container to impersonate Message Queuing)