hdu 2199 （二分）

链接：http://acm.hdu.edu.cn/showproblem.php?pid=2199

Can you solve this equation?

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 8595    Accepted Submission(s): 3957

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!

 

------------------------------------------------------------------------------------------------------------、

 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <iostream>
 #include <algorithm>
 #include <math.h>
 #define eps 1e-8
 using namespace std;

 double fx(double x)
 {
     return *pow(x,)+*pow(x,)+*x*x+*x+;
 }

 int main()
 {
     int n,m,i,j;
     double y;
     double left=,right=,ans;
     scanf("%d",&n);
     while(n--)
     {
         scanf("%lf",&y);
         left=0.0,right=100.0;
         //ans=-100000;
         bool flag=true;
         while(right-left>eps)
         {
             double mid=(left+right)/2.0;
             if(fx(mid)-y< )
                  left=mid+eps;
             else right=mid-eps;
             //if()flag=false;
         }
         if(y>fx() || y<fx())
             printf("No solution!\n");
         else
             printf("%.4lf\n",left);
     }

 }