迭代算法求平方根

#include<stdio.h>#include<math.h>void main()
{ 
    double a,x0,x1;    printf("input a:\n");    scanf("%lf",&a);    if(a<0)printf("ERROR!\n");    else
    { 
        x0=a/2;
        x1=(x0+a/x0)/2;        do
        { 
            x0=x1;
            x1=(x0+a/x0)/2;
        }while(fabs(x0-x1)>=1e-6);
    }    printf("Result:\n");    printf("sqrt(%g)=%g\n",a,x1);
}

运行结果如下：