2
100
-4

1.6152
No solution!

#include<stdio.h>
#include<math.h>
double f(double x){
	return 8*x*x*x*x+7*x*x*x+2*x*x+3*x+6;
}
double binary_search(double x,double y,double n){
	double mid=(x+y)/2;
	if(y-x<=1e-7)	return x;   //刚开始写成 if(fabs(n-f(mid))<=1e-7) return mid; 结果超时,原来还是没理解透二分查找的具体退出边界条件!!!
	else if(f(mid)>=n) return binary_search(x,mid+1e-20,n);   //错了n遍,写成了mid+1e-7!!!
	else return binary_search(mid+1e-20,y,n);	    
}
int main(){
	int T;
	scanf("%d",&T);
	while(T--){
		double y,t;
		scanf("%lf",&y);
        if(y<f(0)||y>f(100)){
        	printf("No solution!\n");
        	continue;
        }
		t=binary_search(0,100,y);
		printf("%.4lf\n",t);
	}
	return 0;
}