HDU2199Can you solve this equation?

Can you solve this equation?
Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 13404    Accepted Submission(s): 5979

Problem Description
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.
 

Input
The first line of the input contains an integer T(1<=T<=100) which means the number of test cases. Then T lines follow, each line has a real number Y (fabs(Y) <= 1e10);
 

Output
For each test case, you should just output one real number(accurate up to 4 decimal places),which is the solution of the equation,or “No solution!”,if there is no solution for the equation between 0 and 100.
 

Sample Input
2
100
-4
 

Sample Output
1.6152
No solution!
 

Author
Redow
 

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#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <queue>
#include <algorithm>
using namespace std;
double g(double x)
{
    return  8*pow(x,4.0) + 7*pow(x,3.0) + 2*pow(x,2.0) + 3*x + 6;
}
int main()
{
    int n;
    double x,y;
    scanf("%d",&n);
    while(n--)
    {
        scanf("%lf",&y);
        double left=0;
        double right=100;
        double mid;
        if(y>=g(0)&&y<=g(100))
        {
            while(right-left>1e-10)
            {


                mid=(left+right)/2;
                if(g(mid)<=y)
                left=mid;
                else
                right=mid;
            }
            printf("%.4lf
",left);
        }
        else
            printf("No solution!
");
    }
}