`为` `啥` `只` `有` `4` `0` `分` `????????`
```cpp
#include<iostream>
#include<algorithm>
using namespace std;
int ans;
int x[100001],N,C;
bool check(int num)
{
int t1=1,t2;
for(int i=2;i<=C;i++)
{
t2=x[t1]+num;
while(x[++t1]<t2)
{
if(x[t1]>N)return false;
}
}
return true;
}
void guess(int l,int r)
{
if(l+1>=r)
{
if(check(r))ans=r;
else ans=l;
return;
}
int mid=(l+r)/2;
if(check(mid))guess(mid+1,r);
else guess(l,mid);
}
int main()
{
cin>>N>>C;
for(int k=1;k<=N;k++)cin>>x[k];
sort(x+1,x+N);
guess(1,1000000);
cout<<ans;
}
```
by chenyanming @ 2019-01-22 20:43:58