UVALive - 3135 Argus

Argus

Time Limit: 3000MS

Memory Limit: Unknown

64bit IO Format: %lld & %llu

Submit StatusDescriptionA data stream is a real-time, continuous, ordered sequence of items. Some examples include sensor data, Internet traffic, financial tickers, on-line auctions, and transaction logs such as Web usage logs andtelephone call records. Likewise, queries over streams run continuously over a period of time and incrementally return new results as new data arrives. For example, a temperature detection system of a factory warehouse may run queries like the following.Query-1: �Every five minutes, retrieve the maximum temperature over the past five minutes.� Query-2: �Return the average temperature measured on each floor over the past 10 minutes.�We have developed a Data Stream Management System called Argus, which processes the queries over the data streams. Users can register queries to the Argus. Argus will keep the queries running over the changingdata and return the results to the corresponding user with the desired frequency.For the Argus, we use the following instruction to register a query:Register Q_num PeriodQ_num (0 < Q_num ≤ 3000) is query ID-number, and Period (0 < Period ≤ 3000) is the interval between two consecutive returns of the result. After Period seconds of register, the result will be returned for thefirst time, and after that, the result will be returned every Period seconds.Here we have several different queries registered in Argus at once. It is confirmed that all the queries have different Q_num. Your task is to tell the first K queries to return the results. If two or more queriesare to return the results at the same time, they will return the results one by one in the ascending order of Q_num.InputThe first part of the input are the register instructions to Argus, one instruction per line. You can assume the number of the instructions will not exceed 1000, and all these instructions are executed at thesame time. This part is ended with a line of �#�.The second part is your task. This part contains only one line, which is one positive integer K (≤ 10000).OutputYou should output the Q_num of the first K queries to return the results, one number per line.Sample Input

Register 2004 200
Register 2005 300
#
5

Sample Output

2004
2005
2004
2004
2005

分析：

优先队列的使用，注意<运算符的重载机制。队列等容器的默认重载运算符是<,而优先队列的特点是大的先出，与<

恰好相反。

ac代码：

#include <iostream>#include<cstdio>#include<queue>using namespace std;struct Item{int qnum,period,time;bool operator <(const Item &a)const{return time>a.time||(time==a.time&&qnum>a.qnum);}};int main(){priority_queue <Item> pq;char s[20];Item item;while(scanf("%s",s)&&s[0]!='#'){scanf("%d%d",&item.qnum,&item.period);item.time=item.period;pq.push(item);//将item入队}int k;scanf("%d",&k);while(k--){Item it=pq.top();pq.pop();printf("%d\n",it.qnum);it.time+=it.period;pq.push(it);//把it入队}return 0;}