Flip the Line

The drill sergeant yells ABOUT FACE! — the whole line must reverse, first becomes last. 🪖

You get a list of nums. Reverse it IN PLACE by swapping the two ends, then the next two, marching inward. Print comma-separated. (No slicing shortcuts!)

Example:

Input: nums = [1, 2, 3, 4, 5] Output: 5,4,3,2,1

Swapping the two ends inward — 1↔5, then 2↔4 — reverses the whole line.