B. Eugeny and Play List

最新推荐文章于 2022-05-12 16:54:35 发布

ECJTU_ACM_余伟伟

最新推荐文章于 2022-05-12 16:54:35 发布

阅读量1k

点赞数

CC 4.0 BY-SA版权

分类专栏： Codeforces_Div.2专题文章标签： Codeforces_B. Eugeny

本文链接：https://blog.youkuaiyun.com/ecjtu_yuweiwei/article/details/8892394

Codeforces_Div.2专题专栏收录该内容

36 篇文章

订阅专栏

探讨音乐爱好者Eugeny如何组织和聆听他的音乐播放列表，包括每首歌曲的重复次数和持续时间，并通过时间戳识别播放的歌曲。本文详细解释了如何计算特定时间点播放的歌曲编号。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

Eugeny loves listening to music. He has n songs in his play list. We know that song number i has the duration of t_i minutes. Eugeny listens to each song, perhaps more than once. He listens to song number i c_i times. Eugeny's play list is organized as follows: first song number 1 plays c₁ times, then song number 2 plays c₂ times, ..., in the end the song number n plays c_n times.

Eugeny took a piece of paper and wrote out m moments of time when he liked a song. Now for each such moment he wants to know the number of the song that played at that moment. The moment x means that Eugeny wants to know which song was playing during the x-th minute of his listening to the play list.

Help Eugeny and calculate the required numbers of songs.

Input

The first line contains two integers n, m (1 ≤ n, m ≤ 10⁵). The next n lines contain pairs of integers. The i-th line contains integers c_i, t_i(1 ≤ c_i, t_i ≤ 10⁹) — the description of the play list. It is guaranteed that the play list's total duration doesn't exceed 10⁹ $\text{[math]}$ .

The next line contains m positive integers v₁, v₂, ..., v_m, that describe the moments Eugeny has written out. It is guaranteed that there isn't such moment of time v_i, when the music doesn't play any longer. It is guaranteed that v_i < v_i + 1 (i < m).

The moment of time v_i means that Eugeny wants to know which song was playing during the v_i-th munite from the start of listening to the playlist.

Output

Print m integers — the i-th number must equal the number of the song that was playing during the v_i-th minute after Eugeny started listening to the play list.

Sample test(s)

input

1 2
2 8
1 16

output

1
1

input

4 9
1 2
2 1
1 1
2 2
1 2 3 4 5 6 7 8 9

output

这题还是比较简单，就是用一般的思路会超时，下面就说下题意吧，估计有些人和我一样看个题目都要半天，谁叫俺们英语差啊.......

题目大概意思是：Eugeny喜欢听歌，他听的歌有些不只听一次，他听的方式是这样的，第一首歌听 c₁次而且每首歌听t1分钟，第二首歌听 c2次而且每首歌听t2分钟....第N首歌听 cn次而且每首歌听tn分钟，输入n,m下面跟着n行，每行有两个整数c_i, t_i意思前面说了然后下面一行有m个整数每个整数代表一个时刻，问在每个时刻，Eugeny在听第几首歌并且输出它.

估计题目懂了，你们也应该能敲出代码来，下面废话不多说，直接看代码吧

代码：

#include<iostream>
const int MAX=100001;
int x[MAX];
int y[MAX];
__int32 z[MAX]={0};//初始化0
using namespace std;
int main()
{
__int32 n,m,i,j,a,p;
cin>>n>>m;
p=1;
cin>>x[1]>>y[1];
z[1]=x[1]*y[1];
for(i=2;i<=n;i++)
{
cin>>x[i]>>y[i];
z[i]+=x[i]*y[i]+z[i-1];
}
for(j=1;j<=m;j++)
{
cin>>a;
while(a>z[p])
p++;
cout<<p<<endl;
}
return 0;
}//如果有问题，或有什么疑惑，可以在评论中提出，小子我看到一定尽力解答