Sort colors

Medium

Given an array of integers containing only 0, 1, and 2, sort the array in-place and return it.

For example, given the following input:

nums = [2, 0, 1, 2, 1, 0]

Your function should return [0, 0, 1, 1, 2, 2].

Array partitioning visualization with three regions for 0s, 1s, and 2s

This is known as the Dutch national flag problem, named after the three-color Dutch flag. The challenge is to sort the array in a single pass using constant extra space.

Try it first

1def sort_colors(nums: list[int]) -> list[int]:
2    # implement sort_colors
3    return nums
4

def sort_colors(nums: list[int]) -> list[int]:
    # implement sort_colors
    return nums

Solution

7 Essential Arrays Coding Interview Problems

Master Arrays by trying the coding challenges below.

1.Trade stock onceEasy
2.AdditionEasy
3.Find the smallestEasy
4.Sort colorsMedium
5.Reorganize numbersHard
6.Maximum subarrayHard
7.Container of waterHard

Previous LessonFind the smallest Next LessonReorganize numbers

Sort colors

Try it first

Solution

7 Essential Arrays Coding Interview Problems

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