http://poj.org/problem?id=2456
#include<cstdio>
#include<algorithm>
#include<string.h>
#include<cstring>
#include<functional>
using namespace std;
int arr[100010],n,c;
bool check(int x)
{
int curr=1,sum=1;
for(int i=2;i<=n;i++)
{
if(arr[i]-arr[curr]>=x)
{
curr=i;
sum++;
if(sum>=c) return true;
}
}
return false;
}
int main(){
while(scanf("%d%d",&n,&c)!=EOF)
{
for(int i=1;i<=n;i++)
{
scanf("%d",arr+i);
}
sort(arr+1,arr+1+n);
int lef=1,rig=1000000000,mid;
while(rig-lef>1)
{
mid=(lef+rig)/2;
if(check(mid))
{
lef=mid;
}
else
{
rig=mid;
}
}
printf("%d\n",lef);
}
}
