CodingEasycod-p020

Subject HashingLevel Entry–Mid~15 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

A teammate wrote this helper to report whether a list contains any duplicate value, but it always returns the wrong answer. Find and fix the bug.

Implement

contains_duplicate(nums: list[int]) → bool

Examples

in[[1,2,3,1]]outtrue

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.

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.