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
sandhuz:
20210502 22:28:50
I recommend first do book allocation problem and here is its explanation:


sharan0105:
20210406 21:47:50
I actually saw a solution to solve this problem but this problem just tells you to what extent binary search can be used


makhan_28:
20210318 06:00:38
The concept which is applied in this problem is mind blowing!!


winner13:
20210316 20:10:07
good question


ishraaq_56789:
20210310 07:50:34
One hell of a problem! Took me one entire day, but I'm happy that at the end of the day I could learn something.


kimg:
20210221 22:23:53
mihimel


mihimel:
20210220 13:58:06
In the example, why can't I put a cow in 9? Then the largest minimum distance would be 4? Or I am not getting the problem? 

kimg:
20210220 08:45:50
Man that's some god tier problem. Really helpful for beginners like me. 

akash_krish123:
20210215 14:02:30
also remember to put an endl in C++ when printing output. Wasted time debugging such an obvious thing to get an accept!! :D otherwise a very good problem to practice binary search implementation. 

spearblaze2:
20210126 05:11:06
Even with binary search method, in JAVA I got Time Limit Exceed(TLE) error. Can anyone help me?. I applied binary search on gap array. 
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 