Any Doubles at All?

The raffle is only fair if no ticket number was printed twice. 🎫

You get the ticket nums. Print all unique if every number is different, or doubles found if any repeats. Hint: what happens to a list's LENGTH when you set() it?

Example:

Input: nums = [5, 8, 2, 9] Output: all unique

set(nums) keeps all 4 values — same length as nums — so nothing was dropped, meaning nothing repeated.

Input: nums = [4, 7, 4] Output: doubles found

set(nums) shrinks to {4, 7}, length 2 instead of 3 — something got dropped, so a repeat happened.