hdu2199（高精度二分模版）

Now,given the equation 8*x^4 + 7*x^3 + 2*x^2 + 3*x + 6 == Y,can you find its solution between 0 and 100;
Now please try your lucky.

#include<iostream>

#include<math.h>

#include<stdio.h>

using namespace std;

double deal(double x)

{

    return 8*pow(x,4)+7*pow(x,3)+2*pow(x,2)+3*x+6;

}

int main()

{

    int t;

    scanf("%d",&t);

    while(t--)

    {

        double x,sum,l=0,r=100;

        scanf("%lf",&sum);

        if(sum<deal(0)||sum>deal(100.0))

        {

            printf("No solution!\n");

            continue;

        }

        else

        {

            double mid;

            int flg=0;

            while(r-l>1e-6)

            {

                 mid=(l+r)/2;

                if(deal(mid)>sum)

                    r=mid;

                else

                    l=mid;

            }

            printf("%.4lf\n",r);

        }

    }

    return 0;

}