75. 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. Use one-pass only.

Double quick sort

class Solution: 
    def sortColors(self, nums: List[int]) -> None: 
        left = 0 
        right = len(nums) - 1 
         
        i = 0 
        while i <= right: 
            if nums[i] == 0: 
                nums[i], nums[left] = nums[left], nums[i] 
                left += 1 
                i += 1 
            elif nums[i] == 2: 
                nums[i], nums[right] = nums[right], nums[i] 
                right -= 1 
            else: 
                i += 1