What is the difference between tail recursion and non-tail recursion?

What is the difference between tail recursion and non-tail recursion?

Tail recursion is a specific form of recursion where the recursive call is the last operation in the function. Non-tail recursion, on the other hand, has additional operations after the recursive call.

Can you give me an example of each?

Sure! In tail recursion, a function calls itself as its last action, like this:

def tail_recursive_function(n, accumulator=1):
    if n == 0:
        return accumulator
    return tail_recursive_function(n-1, n * accumulator)

In non-tail recursion, the function does more after the recursive call:

def non_tail_recursive_function(n):
    if n == 0:
        return 1
    return n * non_tail_recursive_function(n-1)

Why is tail recursion more efficient?

Tail recursion can be optimized by the compiler to avoid adding a new stack frame for each call, which reduces memory usage and prevents stack overflow.

Are there languages that support tail call optimization?

Yes, languages like Scheme, Haskell, and some implementations of JavaScript support tail call optimization, allowing tail-recursive functions to run efficiently.