Can you solve this equation?

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 13674    Accepted Submission(s): 6086

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 <iostream> #include <cmath> #include <iomanip> const double p = 0.000001; using namespace std; double calculate(double x,double Y) {     return 8*pow(x,4)+7*pow(x,3)+2*pow(x,2)+3*x+6;        } double lookup(double left,double right,double Y) {  double mid;         while(right - left > p)   //二分查找         {             mid = (right+left)/2.0;             if(calculate(mid,Y) > Y) right = mid;             else left = mid;         }         return mid;      } int main() {  int T;  double Y,right,left;  cin>>T;  while(T--) {  cin>>Y;  left = 0; right = 100;         if(calculate(left,Y) > Y || calculate(right,Y) <Y)         {             cout<<"No solution!"<<endl;             continue;         }         else        cout<<setiosflags(ios::fixed)<<setprecision(4)<<lookup( left,right, Y)<<endl; } }