hdoj2199Can 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;
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

2100-4

 

Sample Output

1.6152No solution!

 

#include<cstdio>#include<algorithm>#include<string.h>using namespace std;double fun(double x){return 8*x*x*x*x+7*x*x*x+2*x*x+3*x+6;}int main() {double y,mid;int n;scanf("%d",&n);while(n--){    scanf("%lf",&y);if(y<6||y>fun(100))printf("No solution!\n");else{double l=1,r=100;while(r-l>1e-8){ mid=(l+r)/2.0;if(y>fun(mid)){l=mid;}else{r=mid;}}printf("%.4lf\n",mid);}}}