Trouble With Salesforce Interview Question Code

Hello,

I’m having trouble with a code sample I’m working on for a Salesforce interview question for my job. The question is: “How do you find the greatest common divisor of two numbers using recursion?” I’m having difficulty getting the code to work.

I’ve included a sample of the code I’ve written below. I’m having trouble understanding the concept of recursion and how it applies here.

def gcd(a, b): 
    if b == 0: 
        return a 
    return gcd(b, a % b)

Any advice or help would be greatly appreciated. Thank you!