#include<bits/stdc++.h>
using namespace std;
#define ll long long
bool canplace(ll a[],int n,ll max,int cow){
int i;
int cnt=1;
ll last=a[0];
for( i=1;i<n;i++)
{
if(a[i]-last>=max)
{
last=a[i];
cnt++;
if(cnt==cow)
return true;
}
}
return false;
}
int main()
{
int t;
cin>>t;
while(t–){
int n,no;
cin>>n>>no;
ll a[n]={0};
for(int i=0;i<n;i++)
{
cin>>a[i];
}
sort(a,a+n);
ll max=a[n-1]-a[0];
ll s=0;
ll ans;
ll e=max;
while(s<=e){
ll mid=(s+e)/2;
if(canplace(a,n,mid,no))
{
ans=mid;
s=mid+1;
}
else
e=mid-1;
}
cout<<ans<<endl;
}
return 0;
}
my my this code get TLE for the que aggresive cow why