题解 | #求解立方根#

#include<iostream>
#include<math.h>
using namespace std;
int main()
{
    double num;
    double min;
    double max;
    double result;
    while(cin>>num)
    {
        int flag = 0;
        int tmp = 0;
        //负数解决了
        if(num<0)
        {
            num = 0-num;
            flag = 1;
        }
        while(abs(num)<1)
        {
            num *=1000;
            tmp ++;
        }
        min = 0;
        max = num;
        result = (max+min)/2;
        while(abs(result*result*result - num)>0.05)
        {
            if(result*result*result - num >0)
            {
                max = result;
                result = (max+min)/2;
            }
            else if(result*result*result - num <0)
            {
                min = result;
                result = (max+min)/2;
            }
        }
        if(flag == 1)
        {
            result = 0-result;
        }
        while(tmp)
        {
            result /= 10;
            tmp --;
        }
        printf("%.1f\n",result);
    }
    return 0;
}