HDU 2199

这道题，使用二分一样可以过，不过要去1e-6，而不是1e-10，不然就会超时！代码具体如下：
#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
const double maxn=1e-6;
using namespace std;


double ff(double n)
{
    double p;
    p=8*n*n*n*n+7*n*n*n+2*n*n+3*n+6;
    return p;
}


double chaozhao(double  y)
{
   double  x1=0.0,x2=100.0;
   double y1,y2;
   y1=ff(x1);
   y2=ff(x2);
   while(fabs(y1-y2)>maxn)
   {
       double mid;
      mid=(x1+x2)/2;
       if(ff(mid)>=y)
       {
           x2=mid;
           y2=ff(x2);
       }
       else
       {
           x1=mid;
           y1=ff(x1);
       }
   }
    return x1;
}




int main()
{
    int t,i;
    double y;
    while(scanf("%d",&t)!=EOF)
    {
        double min1;
        double max1;
        min1=ff(0.0);
        max1=ff(100.0);
        for(i=1; i<=t; i++)
        {
            scanf("%lf",&y);
            if(y>max1||y<min1)
            {
                cout<<"No solution!"<<endl;
            }
            else
            {
                double k;
                k=chaozhao(y);
                printf("%.4lf\n",k);
            }
        }
    }
    return 0;
}