HDU 1509:Windows Message Queue【優先隊列】

標籤：c++   hdu   優先隊列   排序   

Windows Message Queue Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 4505    Accepted Submission(s): 1794


Problem DescriptionMessage 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. 
InputThere‘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. 
OutputFor 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 結構體裡定義排序的時候我直接用了（node a,node b)，然後一直WA。。。。。糾結了老半天～百度了之後才知道應該用（const node& a,const node& b)雖然不知道為什麼～～AC-code：
#include<stdio.h>#include<string.h>#include<queue>using namespace std;struct node{int k;char s[100];int name;int pri;friend bool operator<(const node& a,const node& b){if(a.pri==b.pri)return a.k>b.k;return a.pri>b.pri;}};int main(){char a[5];node no;int k=1;priority_queue<node>q;while(scanf("%s",a)!=EOF){if(!strcmp(a,"PUT")){scanf("%s%d%d",no.s,&no.name,&no.pri);no.k=k++;q.push(no);}else{if(q.empty()){printf("EMPTY QUEUE!\n");}else{printf("%s %d\n",q.top().s,q.top().name);q.pop();}}}return 0;}

 
Sample Output

EMPTY QUEUE!msg2 10msg1 10EMPTY QUEUE!

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HDU 1509:Windows Message Queue【優先隊列】