AtCoder Grand Contest 019
C
Fountain Walk
AtCoder
⌀ 2495
原题
← BD →
翻译中…

Problem Statement

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In the city of Nevermore, there are $10^8$ streets and $10^8$ avenues, both numbered from $0$ to $10^8-1$. All streets run straight from west to east, and all avenues run straight from south to north. The distance between neighboring streets and between neighboring avenues is exactly $100$ meters.

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Every street intersects every avenue. Every intersection can be described by pair $(x, y)$, where $x$ is avenue ID and $y$ is street ID.

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There are $N$ fountains in the city, situated at intersections $(X_i, Y_i)$. Unlike normal intersections, there's a circle with radius $10$ meters centered at the intersection, and there are no road parts inside this circle.

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The picture below shows an example of how a part of the city with roads and fountains may look like.

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1f931bf0c98ec6f07e612b0282cdb094.png

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City governors don't like encountering more than one fountain while moving along the same road. Therefore, every street contains at most one fountain on it, as well as every avenue.

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Citizens can move along streets, avenues and fountain perimeters. What is the shortest distance one needs to cover in order to get from intersection $(x_1, y_1)$ to intersection $(x_2, y_2)$?

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Constraints

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  • $0 \leq x_1, y_1, x_2, y_2 < 10^8$
  • $1 \leq N \leq 200,000$
  • $0 \leq X_i, Y_i < 10^8$
  • $X_i \neq X_j$ for $i \neq j$
  • $Y_i \neq Y_j$ for $i \neq j$
  • Intersections $(x_1, y_1)$ and $(x_2, y_2)$ are different and don't contain fountains.
  • All input values are integers.
翻译中…

Input

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Input is given from Standard Input in the following format:

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x_1 y_1 x_2 y_2
N
X_1 Y_1
X_2 Y_2
:
X_N Y_N

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Output

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Print the shortest possible distance one needs to cover in order to get from intersection $(x_1, y_1)$ to intersection $(x_2, y_2)$, in meters. Your answer will be considered correct if its absolute or relative error doesn't exceed $10^{-11}$.

翻译中…

样例

Input #1
1 1 6 5
3
3 2
5 3
2 4
Output #1
891.415926535897938
One possible shortest path is shown on the picture below. The path starts at the blue point, finishes at the purple point and follows along the red line. ![c49e52b9b79003f61b8a6efa5dad8ba3.png](https://img.atcoder.jp/agc019/c49e52b9b79003f61b8a6efa5dad8ba3.png)
Input #2
3 5 6 4
3
3 2
5 3
2 4
Output #2
400.000000000000000
![f9090ab734c89424c413f3b583376990.png](https://img.atcoder.jp/agc019/f9090ab734c89424c413f3b583376990.png)
Input #3
4 2 2 2
3
3 2
5 3
2 4
Output #3
211.415926535897938
![4b76416161f27cad20333a9ac636e00f.png](https://img.atcoder.jp/agc019/4b76416161f27cad20333a9ac636e00f.png)
题目信息
题号
agc019_c
时间限制
2 s
内存限制
256 MB

题面与样例版权归 AtCoder 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。