Back to ChallengesSort ColorsMedium 25 min

Sort Colors

Given an array nums with n objects colored red, white, or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white, and blue.

We will use the integers 0, 1, and 2 to represent the color red, white, and blue, respectively.

You must solve this problem without using the library's sort function.

Examples

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

Output: [0,0,1,1,2,2]

The 0s, 1s, and 2s are grouped together.

Input: nums = [2,0,1]

Output: [0,1,2]

The elements are sorted.

Constraints

• n == nums.length
• 1 <= n <= 300
• nums[i] is either 0, 1, or 2.

Complexity Analysis

Time

O(N)

Single pass using three pointers.

Space

O(1)

Sorts in place.

Test Cases

#1 Standard case

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

Expected: [0,0,1,1,2,2]

#2 One of each

Input: nums = [2,0,1]

Expected: [0,1,2]

JavaScript

Output

Click "Run Code" to see output here...