790. 数的三次方根

Posted 2021-05-20 幽殇默

https://www.acwing.com/problem/content/792/

#include<cstdio>
#include<iostream>
using namespace std;
double n;
bool check(double x)
{
	if(x*x*x<=n) return true;
	else return false;
}
int main(void)
{
	cin>>n;
	double l=-1000,r=1000;
	while(r-l>1e-7)
	{
		double mid=(l+r)/2;
		if(check(mid)) l=mid;
		else r=mid;
	}
	printf("%.6lf",l);
	return 0;
}