题解 | #求解立方根#

#include <iostream>
#include <iomanip>
using namespace std;

// 使用二分法求解立方根
double getCubeRoot(double num) {
    // 处理特殊情况
    if (num == 0) return 0;
    
    // 确定二分查找的范围
    double left = min(-1.0, num);
    double right = max(1.0, num);
    
    // 精度设置
    const double eps = 0.0001;  // 误差范围
    
    while (right - left > eps) {
        double mid = (left + right) / 2;
        double cube = mid * mid * mid;
        
        if (cube > num) {
            right = mid;
        } else {
            left = mid;
        }
    }
    
    return left;
}

int main() {
    double num;
    while (cin >> num) {
        double result = getCubeRoot(num);
        cout << fixed << setprecision(1) << result << endl;
    }
    return 0;
}

import java.util.*;

public class Main {
    // 使用牛顿迭代法求解立方根
    public static double getCubeRoot(double num) {
        if (num == 0) return 0;
        
        double x = num;  // 初始值
        double eps = 0.0001;  // 精度
        
        while (true) {
            double nextX = (2 * x + num / (x * x)) / 3;
            if (Math.abs(nextX - x) < eps) {
                return nextX;
            }
            x = nextX;
        }
    }
    
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            double num = sc.nextDouble();
            System.out.printf("%.1f%n", getCubeRoot(num));
        }
    }
}

def get_cube_root(num):
    if num == 0:
        return 0
        
    # 二分法求解
    left = min(-1, num)
    right = max(1, num)
    eps = 0.0001  # 精度
    
    while right - left > eps:
        mid = (left + right) / 2
        cube = mid * mid * mid
        
        if cube > num:
            right = mid
        else:
            left = mid
            
    return left

while True:
    try:
        num = float(input())
        result = get_cube_root(num)
        print(f"{result:.1f}")
    except:
        break