Sort Colors

Problem Statement

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.

Leetcode link

Example 1:

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

Example 2:

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

Constraints:

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

Code

Python Code

class Solution:
    def sortColors(self, nums: List[int]) -> None:
        """
        Do not return anything, modify nums in-place instead.
        """
        curr = 0
        for _ in range(len(nums)):
            if nums[curr] == 0:
                nums.pop(curr)
                nums.insert(0, 0)
                curr += 1
            elif nums[curr] == 2:
                nums.pop(curr)
                nums.append(2)
            else:
                curr += 1
        return