求解立方根 (HJ107)

一：解题思路

这道题目和 leetcode69 题，求解x的平方根有些类似。都是采用二分的思想来做，可以对比分析。 

二：完整代码示例 (C++版和Java版)

C++:

#include <iostream>

using namespace std;

double getCubeRoot(double input)
{
    double low = 0;
    double high = input;

    while ((high-low)>=0.001)
    {
        double mid = low + (high-low) / 2;
        double mid3 = mid * mid*mid;
        if (input == mid3) return mid;
        else if (mid3 > input) high = mid;
        else low = mid ;
    }

    return high;
}

int main() 
{
    cout.precision(2);
    double x = 0;

    while (cin >> x)
    {
        cout << getCubeRoot(x) << endl;
    }

    return 0;
}