hdu 2199 Can 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): 1226????Accepted Submission(s): 625

#include <iostream>#include <stdio.h>#include <cmath>using namespace std;const double eps = 1e-12;double x, y;double calc(double x){ return 8*x*x*x*x + 7*x*x*x + 2*x*x + 3*x + 6;}int main(){ int t; double mid, left, right; scanf("%d", &t); while(t--) { scanf("%lf", &y); left = 0; right = 100; if(calc(left) > y || calc(right) < y) { printf("No solution!\n"); continue; } while(right - left > eps) //二分查找 { mid = (right+left)/2.0; if(calc(mid) > y) right = mid; else left = mid; } printf("%.4lf\n", mid); } return 0;}?