Time Limit: 5000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 6320 Accepted Submission(s):
2383
#include<stdio.h>
#include<string.h>
#include<math.h>
#define MAX 10100
#define pi 3.1415926
double a[MAX];
int n,m;
int f(double x)
{
int i,s=0;
for(i=0;i<n;i++)
s+=(int)(a[i]/x);
return s;
}
int main()
{
int j,i,t;
double max,k;
scanf("%d",&t);
while(t--)
{
scanf("%d%d",&n,&m);
for(i=0;i<n;i++)
{
scanf("%lf",&k);
a[i]=k*k*pi;
}
double l=0,r=200000000000.0,mid;
while(r - l > 1e-6)
{
mid = (r + l)/2;
if(f(mid) >= m+1)//算上自己
l=mid;
else
r=mid;
}
printf("%.4lf\n",r);
}
return 0;
}
原文：http://www.cnblogs.com/tonghao/p/4698967.html