http://acm.hdu.edu.cn/showproblem.php?pid=4004

一条线段长度为L，线段上有n个点，最多选取 m-1 个点，使得包括线段端点在内的相邻点之间的最大距离值最小。

最大值最小化问题，显然二分

judge每次选最远点，选出点数不超过m即可

#include <iostream>

#include <cstdio>

#include <cstring>

#include <string.h>

#include<queue>

using namespace std;

int st[500010],len,n,m,i,j,maxx,fuck,x,flag,left,right,mid;

bool judge(int cao)

{

    int dis = 0, count = 1, i;

    if(st[0] - dis > cao)

        return 0;

    for(i = 1; i <= n; i++)

    {

        if(st[i] - dis > cao)

        {

            dis = st[i-1];

            if(st[i]-dis > cao)

                return 0;

            count++;

        }

    }

    if(count > m)

        return 0;

    return 1;

}

int main()

{

    while(~scanf("%d%d%d",&len,&n,&m))

    {

    memset(st,0,sizeof(st));

    for(i = 1;i <= n;i++) scanf("%d",&st[i]);

    sort(st,st+n+1);

    n++;

    fuck = n - m;

    st[n] = len;

    int left = 0,right = len;

    while(left < right)

    {

        mid = (left + right)/2;

        if(judge(mid)) right = mid;

        else left = mid+1;

    }

    printf("%d\n",right);

    }

    return 0;

}