---
category_name: medium
problem_code: OPTSSET
problem_name: 'Optimal Subset'
languages_supported:
- ADA
- ASM
- BASH
- BF
- C
- 'C99 strict'
- CAML
- CLOJ
- CLPS
- COB
- 'CPP 4.3.2'
- 'CPP 6.3'
- CPP14
- CS2
- D
- ERL
- FORT
- FS
- GO
- HASK
- ICK
- ICON
- JAVA
- JS
- kotlin
- 'LISP clisp'
- 'LISP sbcl'
- LUA
- NEM
- NICE
- NODEJS
- 'PAS fpc'
- 'PAS gpc'
- PERL
- PERL6
- PHP
- PIKE
- PRLG
- PYPY
- PYTH
- 'PYTH 3.5'
- RUBY
- rust
- SCALA
- 'SCM chicken'
- 'SCM guile'
- 'SCM qobi'
- ST
- swift
- TCL
- TEXT
- WSPC
max_timelimit: '8'
source_sizelimit: '50000'
problem_author: chemthan
problem_tester: melfice
date_added: 21-09-2017
tags:
- chemthan
- chemthan
- ltime53
- maths
- medium
- optimization
editorial_url: 'https://discuss.codechef.com/problems/OPTSSET'
time:
view_start_date: 1509210000
submit_start_date: 1509210000
visible_start_date: 1509210000
end_date: 1735669800
current: 1514816021
layout: problem
---
All submissions for this problem are available.### Read problems statements in [Mandarin chinese](http://www.codechef.com/download/translated/LTIME53/mandarin/OPTSSET.pdf), [Russian](http://www.codechef.com/download/translated/LTIME53/russian/OPTSSET.pdf) and [Vietnamese](http://www.codechef.com/download/translated/LTIME53/vietnamese/OPTSSET.pdf) as well.
Problem description.
You are given a convex polygon of **n** vertices **P1, P2, ..., Pn** (in counter-clock or clock order). Each vertex is assigned with a weight **wi**.
Find a subset of vertices that **includes vertex 1**.
**1 = i1 2 k ≤ n** that maximizes ratio:
**(dist(i1, i2) + dist(i2, i3) + ... + dist(ik, i1)) / (wi1 + wi2 + ... + wik)**.
Where **dist(i, j)** refers to Euclidean distance between two points **Pi, Pj**.
### Input
The first line contains an integer **T** denotes the number of test cases. Each test case is describes as follow:
An integer **n** on a single line.
**n** next lines, each line contains two integers, that is coordinates of **i**-th vertex
The last line contains **n** space-seperated integer, denotes weight of vertex.
### Output
Each testcase output the maximum ratio can reach on a single line.
Your answer will be considered correct if it has an absolute error less then **10-6**.
### Constraints
- **1 ≤ T ≤ 10**
- **3 ≤ n ≤ 105**
- The sum of **n** over all test cases is at most **2.105**
- 0 ≤ all coordinates ≤ **109**
- **1 ≤ wi ≤ 105**
Subtask:
- Subtask #1 (10 points): **n ≤ 15**
- Subtask #2 (30 points): **n ≤ 1000**
- Subtask #3 (60 points): original constrains
### Example
<pre><b>Input:</b>
3
3
0 0
1 5
2 9
4 4 20
4
0 0
1 5
2 7
3 6
12 15 12 11
5
0 0
1 5
2 8
3 9
4 8
12 11 18 2 7
<b>Output:</b>
1.274754878
0.606675824
1.355261854
</pre>