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
king_tsar:
20180727 10:35:56
Last edit: 20180727 10:41:23 

nitishyadav169:
20180720 05:53:27
Last edit: 20180817 22:06:54 

ironhulk:
20180712 08:23:56
why 1 4 9 is not the answer of given example??


alucard_01:
20180703 07:18:36
Don't see any kind of solution. 

foool:
20180627 09:34:57
Good problem ..Must for beginners... 

nesdi:
20180626 13:17:16
Great one, If you know what is binary search but you aren't able to crack the trick.


sharansh12:
20180617 06:44:11
AC in one go : )


karan_yadav:
20180616 20:22:48
0.01s


mahadi97:
20180614 22:13:04
If you don't get the it, just read Topcoder tutorial carefully.


lapmid:
20180613 22:18:47
why 1,4,9 is not in answer , largest minimum distance will be 4 n this case 
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 