剪绳子

#include <bits/stdc++.h>
using namespace std;

int n, m;

const int N = 1e6 + 3;

const double eps = 1e-4;

int a[N];

bool check(double x){  //判断是否满足条件
    int cnt = 0;
    for(int i = 0; i < n; i ++){
        cnt += int(a[i] / x);
        if(cnt >= m) return 1;  //当前分割数量已经满足，提前返回 true
    }
    return 0;
}

void solve(){
    cin >> n >> m;
    for(int i = 0; i < n; i ++) cin >> a[i];
    double l = 0, r = 1e9;
    while(l < r){
        double mid = (l + r) / 2;
        if(check(mid)) l = mid;  //满足条件，说明绳子有可能更长
        else r = mid;  //不满足条件，说明绳子需要缩短
        if(r - l < eps) break;  //差值小于 eps 结束二分
    }
    printf("%.2lf", l);
}

int main(){
    solve();
    return 0;
}