题解 | #求解立方根#

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define min(x,y)?x:y
int main() {
    double num;
    scanf("%lf",&num);
    double numabs=fabs(num);//取输入值的绝对值，简化后续比较。
    double dValue=numabs;
    double minCubeRoot=numabs;
    for(int i=0;i<30;i++)
    {
        double cubeRoot=0+0.1*i;
        double tmp=cubeRoot*cubeRoot*cubeRoot;
        if(tmp==numabs)
        {
            printf("%1.1lf",(cubeRoot*(num/numabs)));
        }
        else if(dValue>fabs(numabs-tmp))//当差值的绝对值最小时，即为立方根
        {
            minCubeRoot=cubeRoot;
            dValue=numabs-tmp;            
        }
    }
    printf("%1.1lf",(minCubeRoot*(num/numabs)));
}