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
arjun_agrawal:
20170905 06:45:06
Thought this question in a backward manner. Try to search for the answer in a binary search fashion and check its feasibility 

pkgleb:
20170827 18:47:35
First, I found solution using Indexed priority queue, but after topcoder's article lecture the solution just show up :) 

kspoj:
20170824 20:29:26
Quora helped :) 

iket0512:
20170820 07:29:56
Last edit: 20170820 07:30:22 

suchith:
20170805 20:00:23
nice problem


omaragha:
20170803 16:48:57
Nice BS Problem


kotal_kahn:
20170725 14:56:37
At last after understanding from both Topcoder binary search and the Quora answer


grb_avatar:
20170723 23:40:32
if u having any problem read this link


i_insist:
20170717 07:46:17
don't forget to add new line (cout<<endl) at the end. 

siddiboy:
20170714 08:20:37
any way to do it in O(N)?? 
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 