【二分答案】丢瓶盖

P1316 丢瓶盖

一题学会二分答案系列qwq

#include<cstdio>
#include<iostream>
#include<algorithm>
#define sz 100010
using namespace std;
int n,m,ans=0,xz;
int dis[sz];
int judge(int x) {
    int i = 1, tot = 0, now = 1;
    while(i < n) {
        i++;
        if(dis[i] - dis[now] < x) {
    //        cout<<i<<' '<<now<<endl;
            tot++;
            continue;
        }
        else now = i;
    }
    return tot;
}
int main() {
    scanf("%d%d",&n,&m);
    xz = n-m;
    int x = 0, y;
    for(int i = 1; i <= n; i++) scanf("%d",&dis[i]);
    sort(dis+1,dis+n+1);
    int l = 1, r = dis[n];
    while(l<=r) {
        int mid = (l+r)>>1;
    //    cout<<mid<<' ';
        int abc = judge(mid);
    //    cout<<abc<<endl;
        if(abc <= xz){
            ans = mid;
            l = mid + 1;
        }
        else if(abc>xz) r = mid - 1;
    }
    cout<<ans;
    return 0;
}