牛顿迭代法,供参考:
#include <stdio.h>
#include <math.h>
#define Eps 1e-10
double mysqrt(double x)
{
double x0 = x;
while (fabs(x0 * x0 - x) > Eps)
x0 = 0.5 * (x0 + x / x0);
return x0;
}
int main()
{
double x = 0.25;
printf("%.10f", mysqrt(x));
return 0;
}