CSU-ACM 2017夏休み合宿2-二分検索poj-2456 Aggressive cows-最大化最小値

タイトル:
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.
标题:あなたにN個の柵の座標をあげて、あなたはC頭の牛があって、あなたはあなたの牛の距離の間隔ができるだけ遠いことを望んで、どのように牛を放すことを聞いて、すべての牛の間隔の中で最も小さいその間隔を最大にします
考え方:この最大の最小間隔を二分し、実行可能性を判断する.
コード:

#include 
#include 
#include 
#include 
#include 

using namespace std;

int n,c;
int s[111111];

int judge(int dis)
{
    int l=0,r=1;
    int counts=0;
    while(1)
    {
        while(r