HDU 1509 Windows Message Queue

標籤：

題目連結

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 InputGETPUT msg1 10 5PUT msg2 10 4GETGETGET  Sample OutputEMPTY QUEUE!msg2 10msg1 10EMPTY QUEUE!

 題解：優先隊列，寫的時候運算子多載一直出問題，還是不懂。而且剛開始沒有加idx這個成員，就一直WA，看了看題目也沒發現什麼詭異的地方，最後看了幾個題解，加上了idx就AC了，也不知道是為什麼。

#include <cstdio>#include <iostream>#include <string>#include <sstream>#include <cstring>#include <stack>#include <queue>#include <algorithm>#include <cmath>#include <map>#define PI acos(-1.0)#define ms(a) memset(a,0,sizeof(a))#define msp memset(mp,0,sizeof(mp))#define msv memset(vis,0,sizeof(vis))using namespace std;//#define LOCALstruct task{    char name[50];    int value,pri,idx;    friend bool operator < (task a,task b)    {        if(a.pri==b.pri)        {            return b.idx<a.idx;        }        return b.pri<a.pri;    }} t;int main(){#ifdef LOCAL    freopen("in.txt", "r", stdin);#endif // LOCAL    ios::sync_with_stdio(false);    priority_queue<task> q;    //while(!q.empty())q.pop();    char com[5];    int k=0;    while(cin>>com)    {        if(com[0]==‘G‘)        {            if(q.empty())printf("EMPTY QUEUE!\n");            else printf("%s %d\n",q.top().name,q.top().value),q.pop();        }        else        {            cin>>t.name>>t.value>>t.pri;            t.idx=++k;            q.push(t);        }    }    return 0;}

 

HDU 1509 Windows Message Queue