CF1381E.Origami

普及/提高-

通过率:0%

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题目描述

After being discouraged by 13 time-limit-exceeded verdicts on an ugly geometry problem, you decided to take a relaxing break for arts and crafts.

There is a piece of paper in the shape of a simple polygon with nn vertices. The polygon may be non-convex, but we all know that proper origami paper has the property that any horizontal line intersects the boundary of the polygon in at most two points.

If you fold the paper along the vertical line x=fx=f , what will be the area of the resulting shape? When you fold, the part of the paper to the left of the line is symmetrically reflected on the right side.

Your task is to answer qq independent queries for values f1,,fqf_1,\ldots,f_q .

输入格式

The first line contains two integers nn , qq ( 3n105,1q1053\le n\le 10^5, 1\le q\le 10^5 ) — the number of polygon vertices and queries, respectively.

Each of the next nn lines contains two integers xix_i , yiy_i ( xi,yi105|x_i|, |y_i|\le 10^5 ) — the coordinates of the ii -th point of the polygon. The polygon has an edge connecting each pair of adjacent points in the input, and also an edge between (x1,y1)(x_1,y_1) and (xn,yn)(x_n,y_n) . It is guaranteed that the polygon is non-degenerate and that any horizontal line intersects the boundary of the polygon in at most two points. In particular, no boundary edge is strictly horizontal. Two adjacent sides may be collinear.

Each of the next qq lines contains a single integer fif_i ( minj=1n(xj)<fi<maxj=1n(xj)\min\limits_{j=1}^n(x_j)< f_i< \max\limits_{j=1}^n(x_j) ) — the xx -coordinate of the ii -th fold query. It is guaranteed that all fif_i are distinct.

输出格式

For each query, output the area AiA_i of the paper if you fold it along the line x=fix=f_i .

Your answer is considered correct if its absolute or relative error does not exceed 10410^{-4} .

Formally, let your answer be aa , and the jury's answer be bb . Your answer is accepted if and only if abmax(1,b)104\frac{|a - b|}{\max{(1, |b|)}} \le 10^{-4} .

输入输出样例

  • 输入#1

    4 7
    0 10
    10 0
    0 -10
    -10 0
    -9
    -5
    -1
    0
    1
    5
    9

    输出#1

    199.0000000000
    175.0000000000
    119.0000000000
    100.0000000000
    119.0000000000
    175.0000000000
    199.0000000000
  • 输入#2

    4 1
    0 0
    0 2
    2 4
    2 2
    1

    输出#2

    3.0000000000
  • 输入#3

    9 4
    0 -3
    2 -2
    -1 -1
    0 4
    2 5
    1 6
    -2 3
    -1 1
    -3 0
    0
    -2
    -1
    1

    输出#3

    11.1250000000
    11.7500000000
    10.3446969697
    11.3333333333

说明/提示

The first test, with the fold f=5f=-5 :

The second test, with the fold f=1f=1 :

The third test, with the fold f=1f=-1 :

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