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
saddy_2001:
20200508 22:50:35
this is a nice question for implementation of binary search ! 

shikhar2402_:
20200508 12:19:19
why not choose 1,4,9 

sacsachin:
20200504 18:03:17
Finally AC after 6 WA. 

rohit_mahale:
20200502 12:02:12
good problem...if you dont able to come up with the approach just read some tutorial or watch some explaination videos instead just jump onto the actual solution.


chikku:
20200429 13:08:23
tf does this question mean?


sameerchour:
20200426 19:27:18
Guys , for those who think for largest minimum distance , it should be 1,4,9 , not 1,4,8. Actually , it does not make any difference, because , minimum dist between two cows is (41) = 3 , not (95) = 4 , 4 is not the minimum distance, so we have to output the largest minimum distance we could get , like (12), (41), we could place cow at 1,8,9 , (81) = 7, but then , minimum distance would be (98) = 1 , I hope you understand , because the wordings are very confusing and I was stuck for a long time !! hope this helps !! 

az_09_18je0028:
20200419 09:37:27
AC in one go::)


sudhanshu751:
20200405 08:12:07
For everyone that is stuck/not able to think of the logic, check out the TopCoder tutorial for Binary Search [discrete binary search] .


blackhat_130:
20200319 20:51:11
You should think of doing binary search on difference.


prabhudeen:
20200317 20:00:38
nice question on binary search and gready approch takes time to come up the right solution. 
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 