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[];

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

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

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