Find Maximum Window Sum
Company: DoorDash
Role: Analytics Engineer
Category: Coding & Algorithms
Difficulty: hard
Interview Round: Technical Screen
Given an integer array nums and an integer k, write code to find the maximum sum of any contiguous subarray of length exactly k. Assume 1 <= k <= len(nums), values may be negative, and the expected solution should run in O(n) time using a sliding-window approach.
Quick Answer: This question evaluates array manipulation, algorithmic efficiency, and familiarity with the sliding-window technique for computing metrics over fixed-length contiguous subarrays.
Return the maximum sum of any contiguous subarray of length exactly k.
Constraints
- Inputs are provided as Python literals matching the function signature.
- Return a deterministic exact-match result.
Examples
Input: ([1,2,3,4,5], 2)
Expected Output: 9
Explanation: Best length-two window.
Input: ([-5,-2,-3], 2)
Expected Output: -5
Explanation: All negative.
Hints
- Choose a representation that makes the core operation simple.
- Handle empty and boundary inputs before the main algorithm.