Practice: Sliding Window Maximum

Problem: https://leetcode.com/problems/sliding-window-maximum/

Recognition reminder: a fixed window of size k slides across the array, and for each position you report the maximum inside the window. The naive scan is O(n*k); the lesson here is the monotonic deque that brings it down to O(n).

Before you start (the five-beat rhythm)

  1. Your Pattern Card for this week is already written.
  2. Name the pattern aloud and write your approach as a plain-English comment before any code.
  3. Struggle floor: 25 minutes unaided. No hints, no AI, no Discuss tab.
  4. If stuck past the floor, ask the tutor for a hint. Six rungs, one per ask.
  5. Debrief in your commit message before moving to the next problem.

Your target

Fill these in yourself before you look at anyone else’s solution:

Target time complexity:  ____
Target space complexity: ____

There is an O(n*k) approach that re-scans each window, and a faster one using a tool from this week’s refresher (collections.deque). Get the direct way clear first, then find why a deque holding indices in decreasing order gives you the max in O(1) per step. Write the complexity of each in your debrief.

Where your code goes

Write your solution in your own work repo (see getting-started.md), not in this folder. This folder ships only the problem spec and a provided-example test (tests/test_provided.py) so you can check the given cases locally before you submit to LeetCode’s judge. The judge is the oracle; the tutor will not confirm your answer by reading it.

Debrief (paste into your commit message) 

1. What pattern did this turn out to be?
2. What was the trigger phrase or input shape that should have made me reach for it?
3. What was the time and space complexity, and what would dominate at scale?
4. What edge case would have broken my first attempt?
5. What would I do differently in three days when I see this cold?