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EasyPrep Room Coding #423

Close duplicates

CodingAlgorithms & data structuresEntry–Mid~11 min

Given a list of integers and an integer window k, decide whether the list contains two equal values that sit close together: return true if there exist indices i < j with nums[i] == nums[j] and j - i <= k, and false otherwise. For example, [1, 2, 3, 1] with k = 3 is true (the two 1s are 3 apart), but the same list with k = 2 is false. A full pairwise comparison is too slow for large inputs — aim for one pass.

Implement
has_close_duplicate(nums: list[int], k: int) → bool
Examples
in[[1,2,3,1],3]outtrue
in[[1,2,3,1],2]outfalse
What 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.

0:00 of about 11 min
InputExpectedGot
[[1,2,3,1],3]truenot run yetsample
[[1,2,3,1],2]falsenot run yetsample