ACM-ICPC 2017 Hong Kong E.Base Station Sites

ACM-ICPC 2017 Hong Kong E.Base Station Sites

标签（空格分隔）： 算法竞赛

---

当时傻乎乎的取点，还讨论了半天，看着榜上刷出这道题的人越来越多，知道是道水题却做不出来，好尴尬。最后才想到是二分法枚举可能的长度。

#include <iostream>
#include <cstdio>
#include <algorithm>
#define N 100050
using namespace std;
int a[N];
int main()  {
    int n,m;
    while (scanf("%d %d",&n,&m)&&n&&m)  {
        for (int i=0;i<n;i++)   scanf("%d",&a[i]);
        sort(a,a+n);
        int left=0,right=a[n-1]-a[0];
        while (left<=right) {
            int mid=(left+right)/2;
            int now=0,cnt=0;
            for (int i=0;i<n;i++)   {
                if (a[i]-a[now]>=mid)   {
                    cnt++;
                    now=i;
                }
            }
            if (cnt>=m-1)   left=mid+1;
            else if (cnt<m-1)   right=mid-1;
        }
        printf("%d\n",left-1);
    }
    return 0;
}