Sliding Window Maximum

Onsite coding prompt equivalent to Sliding Window Maximum. Given `nums` and window size `k`, return the maximum value in every contiguous window of length `k`. Requirements Input: integer array nums and integer window size k. For every contiguous subarray of length k, output the maximum element in that window. Preserve the original left-to-right window order in the output. Expected performance is better than scanning each window independently. Notes The prompt appeared in a problem-solving round paired with another hard array prompt, so time management matters. Clarify edge cases: k == 1, k == len(nums), duplicate maxima, and negative values. Preparation Drill the monotonic queue implementation until enqueue/dequeue expiry logic is automatic. Practice explaining why stale indices must be removed before reading the front of the deque.