CodingHardcod-g169

Subject Bit manipulationLevel Senior–Staff~25 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Every element in the integer array nums appears exactly three times except for one element which appears exactly once. Return that single element. Inputs are non-negative integers. Solve it with O(n) time and O(1) extra space (do not use a hash map or sort).

Implement

single_number_iii(nums: list[int]) → int

Examples

in[[2,2,3,2]]out3

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.