AGGRCOW - Aggressive cows


Farmer John has built a new long barn, with N (2 <= N <= 100,000) stalls. The stalls are located along a straight line at positions x1,...,xN (0 <= xi <= 1,000,000,000).

His C (2 <= C <= N) cows don't like this barn layout and become aggressive towards each other once put into a stall. To prevent the cows from hurting each other, FJ wants to assign the cows to the stalls, such that the minimum distance between any two of them is as large as possible. What is the largest minimum distance?

Input

t – the number of test cases, then t test cases follows.
* Line 1: Two space-separated integers: N and C
* Lines 2..N+1: Line i+1 contains an integer stall location, xi

Output

For each test case output one integer: the largest minimum distance.

Example

Input:

1
5 3
1
2
8
4
9

Output:

3

Output details:

FJ can put his 3 cows in the stalls at positions 1, 4 and 8,
resulting in a minimum distance of 3.


hide comments
sandeep48: 2019-03-26 18:46:53

AC in one go..easy implementation of binary search

aj_254: 2019-03-09 22:37:35

Ac in third go .. well i get help from qoura and topcoder to solve this question

walter_whitee: 2019-03-08 20:08:56

AC in one go

aujasvit_datta: 2019-03-06 05:40:38

Can't it be 1,4,9 instead of 1,4,8

aj_254: 2019-02-24 12:45:19

should i try in python or leave it?

traitorakali: 2019-02-18 09:30:47

Can it be 1,4 and 9 instead of 1,4 and 8 ? Thank you uwu

zarif_2002: 2019-02-07 06:34:23

AC in one go.

deepakjain1998: 2019-01-30 14:15:46

first attempt AC !!! Thanks to Akash Yadav Sir and Sudama Sir

vickyand_27: 2019-01-02 16:54:56

my complexity is O(c*log(max(x[i]))*logn)

arpitkaushik18: 2018-12-18 08:14:40

Nice Problem on Binary Search : )


Added by:Roman Sol
Date:2005-02-16
Time limit:2s
Source limit:10000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All
Resource:USACO February 2005 Gold Division