JAVA 代码

import java.util.Scanner;
import java.io.BufferedInputStream;

public class Main {
    //程序入口
    public static void main(String[] args) {
        Scanner in = new Scanner(new BufferedInputStream(System.in));
        double n = in.nextDouble();
        double l = -10000;
        double m = 10000;
        while(m - l > 1e-8){
            double mid = (m + l) / 2;

            if(mid * mid * mid >= n)
                m = mid;
            else
                l = mid;
        }

        System.out.println(String.format("%.6f", l)); // 保留 6位小数

    }

}