数的三次方根

没啥说的，别写成l=-x,r=x就行

Java样例

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double x = sc.nextFloat();
        double l=-10000, r=10000;

        while(r-l>1e-7) {
            double mid = (l+r)/2;
            if(mid*mid*mid>=x) r=mid;
            else l=mid;
        }
        System.out.printf("%.6f",l);
    }
}