Code RoomDuplicate check returns inverted
EasyPrep Room Coding #1582

Duplicate check returns inverted

CodingAlgorithms & data structuresEntry–Mid~15 min

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.

0:00 of about 15 min
InputExpectedGot
[[1,2,3,1]]truenot run yetsample