HDU2899超级简单基础的三分

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<string>
#include<vector>
#include<queue>
#include<cmath>
#include<memory.h>

using namespace std;

#define eps 1e-9
double y;

double detal(double x)
{
double ans;
ans=6*x*x*x*x*x*x*x+8*x*x*x*x*x*x+7*x*x*x+5*x*x-y*x;
return ans;
}

int main()
{
int t;
double mid,mmid,r,l,ans1,ans2;
cin>>t;
while(t--)
{
cin>>y;
r=100.0,l=0.0;
while(r-l >= eps)
{
mid=(l+r)/2;
mmid=(mid+r)/2;
ans1=detal(mid);
ans2=detal(mmid);
if(ans1<ans2)
r=mmid;
else
l=mid;
}
printf("%.4lf\n",ans1<ans2?ans1:ans2);
}
}