UVALive 3635 分派

https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1636

http://7xjob4.com1.z0.glb.clouddn.com/7f2d26dff99d9cc95e81c18e10aea4f5

题意：每个人分到面积相同的整块派，求能分到的最大面积

思路：二分查找面积为x的派看是否能分足够的块数

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

const double pi=acos(-1.0);

int r;
int n,f;
double s[10005];

int check(double c)
{
    int i,j,sum=0;
    for(i=1;i<=n;i++)
        sum+=floor(s[i]/c);
    if(sum>=f+1)
        return 1;
    else
        return 0;
}

int main()
{
    int T;
    int i,j;
    scanf("%d",&T);
    while(T--)
    {
        double L=0,R=0;
        scanf("%d %d",&n,&f);
        for(i=1;i<=n;i++)
        {
            scanf("%d",&r);
            s[i]=pi*r*r;
            R=max(R,s[i]);
        }

        while(R-L>1e-5)
        {
            double M=(L+R)/2;
            if(check(M)==1)
                L=M;
            else
                R=M;
        }
        printf("%f
",L);
    }
    return 0;
}