Codeforces Round 310 (Div. 1)
D
Case of a Top Secret
Codeforces
2500
原题
← CE →
翻译中…

Andrewid the Android is a galaxy-famous detective. Now he is busy with a top secret case, the details of which are not subject to disclosure.

翻译中…

However, he needs help conducting one of the investigative experiment. There are $*n*$ pegs put on a plane, they are numbered from $1$ to $*n*$, the coordinates of the $*i*$-th of them are $(*x*_{*i*}, 0)$. Then, we tie to the bottom of one of the pegs a weight on a tight rope of length $*l*$ (thus, its coordinates will be equal to $(*x*_{*i*},  - *l*)$, where $*i*$ is the number of the used peg). Then the weight is pushed to the right, so that it starts to rotate counterclockwise. At the same time, if the weight during rotation touches some of the other pegs, it then begins to rotate around that peg. Suppose that each peg itself is very thin and does not affect the rope length while weight is rotating around it.

翻译中…

image

翻译中…

More formally, if at some moment the segment of the rope contains one or more pegs in addition to the peg around which the weight is rotating, the weight will then rotate around the farthermost one of them on a shorter segment of a rope. In particular, if the segment of the rope touches some peg by its endpoint, it is considered that the weight starts to rotate around that peg on a segment of the rope of length $0$.

翻译中…

At some moment the weight will begin to rotate around some peg, without affecting the rest of the pegs. Andrewid interested in determining the number of this peg.

翻译中…

Andrewid prepared $*m*$ queries containing initial conditions for pushing the weight, help him to determine for each of them, around what peg the weight will eventually rotate.

翻译中…

Input

翻译中…

The first line contains integers $*n*$ and $*m*$ ($1 ≤ *n*, *m* ≤ 2·10^{5}$) — the number of pegs and queries.

翻译中…

The next line contains $*n*$ integers $*x*_{1}, *x*_{2}, ..., *x*_{*n*}$ ($- 10^{9} ≤ *x*_{*i*} ≤ 10^{9}$) — the coordinates of the pegs. It is guaranteed that the coordinates of all the pegs are distinct integers.

翻译中…

Next $*m*$ lines contain the descriptions of the queries of pushing the weight, each consists of two integers $*a*_{*i*}$ ($1 ≤ *a*_{*i*} ≤ *n*$) and $*l*_{*i*}$ ($1 ≤ *l*_{*i*} ≤ 10^{9}$) — the number of the starting peg and the length of the rope.

翻译中…

Output

翻译中…

Print $*m*$ lines, the $*i*$-th line should contain the number of the peg around which the weight will eventually rotate after the $*i*$-th push.

翻译中…

Note

翻译中…

Picture to the first sample test:

翻译中…

image

翻译中…

Picture to the second sample test:

翻译中…

image

翻译中…

Note that in the last query weight starts to rotate around the peg 1 attached to a rope segment of length 0.

翻译中…

样例

Input #1
3 2
0 3 5
2 3
1 8
Output #1
3
2
InputCopy OutputCopy
Input #2
4 4
1 5 7 15
1 4
2 15
3 16
1 28
Output #2
2
4
3
1
InputCopy OutputCopy
题目信息
题号
555D
时间限制
2 s
内存限制
256 MB
标签
二分
模拟
数学

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。