Code Room
CodingMediumcod-p042
Subject Two pointersLevel Mid–Senior~25 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given an array of 0s, 1s, and 2s, sort it in a single pass using constant extra space. Return the sorted array.

Implement
sort_colors(nums: list[int]) → list[int]
Examples
in[[2,0,2,1,1,0]]out[0,0,1,1,2,2]
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.

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.