1001 Can you solve this equation?

1001 Can you solve this equation?

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;<br>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<br>100<br>-4<br>
  
  

 

Sample Output

  
  

   
   1.6152<br>No solution!<br>
  
  
  
  

   
   用
   
   二分搜索
  
  
  
  

   
   #include <stdio.h>  
#include <iostream>  
#include <cmath>  
using namespace std;  
double y;  
double fc(double x)  
{  
    return 8*pow(x,4)+7*pow(x,3)+2*x*x+x*3+6-y;  
}  
int main()  
{  
    int n;  
    scanf("%d",&n);  
    while(n--)  
    {  
        double l=0;  
        double r=100;  
        double x=-1;  
        scanf("%lf",&y);  
        if(fc(0)>0||fc(100.0)<0)  
        {  
            printf("No solution!\n");  
            continue;  
        }  
        else  
        {  
            while(l<r)  
            {  
                double mid=(l+r)/2;  
                if(fc(mid)<0.000001&&fc(mid)>-0.000001)  
                {  
                    x=mid;  
                    break;  
                }  
                else if(fc(mid)<0)  
                    l=mid;  
                else  
                    r=mid;  
            }  
            if(x==-1)  
                printf("No solution!\n");  
            else  
                printf("%.4f\n",x);  
        }  
    }  
    return 0;  
}