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 spaceseparated 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
aj_254:
20190309 22:37:35
Ac in third go .. well i get help from qoura and topcoder to solve this question 

walter_whitee:
20190308 20:08:56
AC in one go


aujasvit_datta:
20190306 05:40:38
Can't it be 1,4,9 instead of 1,4,8 

aj_254:
20190224 12:45:19
should i try in python or leave it?


traitorakali:
20190218 09:30:47
Can it be 1,4 and 9 instead of 1,4 and 8 ? Thank you uwu 

zarif_2002:
20190207 06:34:23
AC in one go. 

deepakjain1998:
20190130 14:15:46
first attempt AC !!! Thanks to Akash Yadav Sir and Sudama Sir 

vickyand_27:
20190102 16:54:56
my complexity is O(c*log(max(x[i]))*logn)


arpitkaushik18:
20181218 08:14:40
Nice Problem on Binary Search : )


angrysum:
20181126 10:35:15
@lapmid, you need to find that particular positions set for cows such that minimum distance of that particular set is largest among other sets. 
Added by:  Roman Sol 
Date:  20050216 
Time limit:  2s 
Source limit:  10000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All 
Resource:  USACO February 2005 Gold Division 