AC in one go !!!
good question on BinarySearch !!!
must do !!

AC in one go! Good question but sample test case could've been better.

Finally One Correct in One Go!!

Really good question about binary search.

My code working on my computer but showing wrong answer in SPOJ

#include<bits/stdc++.h>
using namespace std;
int barn, cow, temp;
vector<int> pos;

bool place_them(int mid)
{
int count=1, start=pos[0];
for(int i=0; i<barn; i++)
{
if(pos[i]-start >= mid)
{
count++;
start = pos[i];
}
if(count==cow) return 1;
}
return 0;
}

int binary(int lo, int hi)
{
int mid;
while(hi-lo>1)
{
mid = lo + (hi-lo)/2;
if(place_them(mid)) lo = mid;
else hi = mid;
}
return mid;
}

int main()
{
int t;
cin >> t;
while(t--)
{
cin >> barn >> cow;
pos.clear();

for(int i=0; i<barn; i++)
{
cin >> temp;
pos.push_back(temp);
}
sort(pos.begin(), pos.end());
int lo, hi;
lo = 0;
hi = pos[barn-1] - pos[0] + 1;
temp = binary(lo, hi);
cout << temp << endl;
}
return 0;
}