Heron 算法递归 C#

Question

I'm trying to implement the heron algorithm recursively in C#. I don't really understand where my code is wrong:

Given definition of algorithm:

x[n+1] = (p-1) /p*x[n] + a/p*x[n]^p-1
Where xo = 1 and p root a

public static double Heron(int x,int p,int a)
{
    if(x == 0)
    {
        return 1.0;
    }

    return ((p-1.0)/p)*Heron(--x,p,a)+a/(p*Math.Pow(Heron(--x,p,a),--p));

}

eg Heron(1,3,5) should return 7/3;

Answer 1

Don't modify the value of x and p in your expression.

Just use

double x_n = Heron(x-1,p,a);
return ((p-1.0)/p)*x_n+a/(p*Math.Pow(x_n,p-1));

I have also kept the value of the recursion in x_n so it does not get called twice.