Space complexity of recursive algorithm

Question

I was asked at an interview, the efficient way to solve a problem checking for pallindrome.

Now i can do two things:

1. starting from i = 0 to i = n/2 and co

Answer 1

In theory they have the same space complexity; it largely depends on whether tail recursion can be optimized.

If so, the stack gets replaced at every recursion so it doesn't incur a penalty.