【UVALive 3135 --- Argus】优先队列

Description

A 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 and telephone 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 changing data 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 P eriod

Q num (0 < Qnum ≤ 3000) is query ID-number, and P eriod (0 < P eriod ≤ 3000) is the interval between two consecutive returns of the result. After P eriod seconds of register, the result will be returned for the first time, and after that, the result will be returned every P eriod 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 queries are to return the results at the same time, they will return the results one by one in the ascending order of Q num.

Input

The 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 the same 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).

Output

You 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

题意

有一些命令 abc num period，每period秒发生一个num事件，输出前k个时间的num。

解题思路

一个结构体存num和对应的period，然后再把下一次会发生的时间t存下来，优先队列将所有下一次发生事件的时间排序，然后每次输出队首，将队首的下一次发生时间加period，再放进队列。

AC代码：

#include 
#include 
#include 
#include 
using namespace std;

struct Node
{
    int num,period,t;
    bool operator<(Node b) const
    {
        if(t!=b.t)
            return t>b.t;
        else
            return num>b.num;
    }
};

int main()
{
    std::ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    string s;
    priority_queue<Node> q;
    while(cin >> s && s!="#") 
    {
        Node node;
        cin >> node.num >> node.period;
        node.t=node.period;
        q.push(node);
    }
    int n;
    cin >> n;
    while(n--)
    {
        Node node=q.top();
        q.pop();
        cout << node.num << endl;
        node.t+=node.period;
        q.push(node);
    }
    return 0;
}