Could someone explain why this function doesn't always return the first element of the list

I have been having a look at some simple recursive functions to wrap my head around the concept. However one example has me a little confused.

The function below uses recursion to obtain the largest integer from a list:

A = [-4, 2, 4]
n = len(A)
def findMaxRec(A, n):
    if (n == 1):
        return A[0]
    else:
        return max(A[n - 1], findMaxRec(A, n - 1))

As n will eventually equal 1 why does the function not always return the first element in the list?

>Solution :

In such cases it might be helpful to just write out what code will be executed. I’ve tried to do that with your function as pseudo-code, where n is replaced with its value:

findMaxRec(A, 3):
    if (3 == 1):
        return A[0]
    else:
        return max(A[3 - 1], 
            findMaxRec(A, 2):
                if (2 == 1):
                    return A[0]
                else:
                    return max(A[2 - 1], 
                        findMaxRec(A, 1):
                            if (1 == 1):
                                return A[0]
                )
    )

Effectively, this results in:

max(A[2], max(A[1], A[0]))

Where the inner call max(A[1], A[0]) = max(2, -4) = 2

And the outer call max(A[2], ...) = max(4, 2) = 4