Code Room
CodingMedium
Question
Given an integer array nums and an integer k, return the total number of contiguous subarrays whose sum equals exactly k. The array may contain negative numbers and zeros. Aim for O(n). Constraints: 1 <= len(nums) <= 2*10^4, -1000 <= nums[i] <= 1000, -10^7 <= k <= 10^7.
Implement
subarray_sum_equals_k(nums: list[int], k: int) → intExamples
in
[[1,1,1],2]out2What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
Learn the concepts
Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.
Run or narrate your approach, then ask the coach.