523D - Statistics of Recompressing Videos模拟，greedy

Posted 2023-01-14 小章鱼哥

D. Statistics of Recompressing Videos time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output

A social network for dogs called DH (DogHouse) has k special servers to recompress uploaded videos of cute cats. After each video is uploaded, it should be recompressed on one (any) of the servers, and only after that it can be saved in the social network.

We know that each server takes one second to recompress a one minute fragment. Thus, any server takesm seconds to recompress am minute video.

We know the time when each of the n videos were uploaded to the network (in seconds starting from the moment all servers started working). All videos appear at different moments of time and they are recompressed in the order they appear. If some video appeared at time s, then its recompressing can start at that very moment, immediately. Some videos can await recompressing when all the servers are busy. In this case, as soon as a server is available, it immediately starts recompressing another video. The videos that await recompressing go in a queue. If by the moment the videos started being recompressed some servers are available, then any of them starts recompressing the video.

For each video find the moment it stops being recompressed.

Input

The first line of the input contains integers n andk (1 ≤ n, k ≤ 5·10⁵) — the number of videos and servers, respectively.

Next n lines contain the descriptions of the videos as pairs of integerss_i, m_i (1 ≤ s_i, m_i ≤ 10⁹), where s_i is the time in seconds when thei-th video appeared andm_i is its duration in minutes. It is guaranteed that all thes_i's are distinct and the videos are given in the chronological order of upload, that is in the order of increasings_i.

Output

Print n numbers e₁, e₂, ..., e_n, wheree_i is the time in seconds after the servers start working, when thei-th video will be recompressed.

Sample test(s) Input

3 2
1 5
2 5
3 5

Output

6
7
11

Input

6 1
1 1000000000
2 1000000000
3 1000000000
4 1000000000
5 1000000000
6 3

Output

1000000001
2000000001
3000000001
4000000001
5000000001
5000000004

题意：  输入一个n和一个k，n个视频k个压缩工具。  每个压缩工具每压缩一分钟视频要花费1秒的时间。后面n行，每行输入两个数，第i行第一个数代表第i个待压缩视频的到达时间，后一个数代表第i个带压缩视频一共有多少分钟。。一个压缩工具压缩完毕后立刻压缩后面未压缩的视频。。视频是排队进来的。。。

思路：此题让我想起了n久以前的一个洗衣服问题。一堆衣服运过来，给一个衣服的数量。有几个洗衣机，每个洗衣机只能洗几件衣服而已。。。不同时间运衣服过来，问最后洗完是什么时间。。。。。实际上是贪心模拟。。
   比如这道题，我模拟k个位置，我用队列建k个位置，初始化为零。。然后，每一个视频运过来，就给第一个位置（视作机器），让他运转，把花费的时间给它，让它到队尾去。。后面每来一个视频，都从队首拿机器，，这样循环输出。。
注意数据还是很大的  long  long。

代码：

<pre name="code" class="cpp">#include<iostream>
#include<cstdio>
#include<cstring>
#include<ctime>
#include<algorithm>
#include <map>
#include <queue>
using namespace std;
//523D  greedy  模拟


queue<long long int> q;

int main()

    long long int n,k,x,y;
    scanf("%lld%lld",&n,&k);
    for(int i=0; i<k; i++)q.push(0);
    while(n--)
    
        scanf("%lld%lld",&x,&y);
        x=max(x,-q.front())+y;
        printf("%lld\\n",x);
        q.pop();
        q.push(-x);