Aggressive cows

题目链接
Description

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 want 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

• Line 1: Two space-separated integers: N and C

• Lines 2..N+1: Line i+1 contains an integer stall location, xi
  Output

• Line 1: One integer: the largest minimum distance
  Sample Input

5 3
1
2
8
4
9

Sample Output

3

Hint

OUTPUT DETAILS:

FJ can put his 3 cows in the stalls at positions 1, 4 and 8, resulting in a minimum distance of 3.

Huge input data,scanf is recommended.

#include<algorithm>
#include<iostream>
#include<cstdio>
using namespace std;
long long int n,c,l,r,x[100005];
int check(int mid){int pos,index;index = 0,pos = x[0];for(int i = 1;i < c;i++){
   //第一个牛已经排好顺序,只需要循环c - 1 次while(pos + mid > x[index]){index++;if(index >= n)return 0;}pos = x[index];}return 1;
}
int main(){scanf("%lld%lld",&n,&c);for(int i = 0;i < n;i++)scanf("%lld",&x[i]);sort(x,x + n);//先排序l = 0,r = x[n - 1] - x[0] - 1;//二分查找板的间距,按照下标进行寻找while(l <= r){long long int mid = l + (r - l) / 2;if(check(mid) == 0)///越界r = mid - 1;elsel = mid + 1;}printf("%lld\n",r);return 0;
}