Adobe·Software Engineer·Technical Phone Screen
- Given an unsorted integer array, find all duplicate numbers. Walk through the trade-offs between different approaches.
- If all values are bounded between 1 and 200, what additional approaches open up? Compare bitmask, counting array, and in-place index marking.
“I jumped straight to hash-set because that's the reflex answer and it is fine, O(n) time, O(n) space.”