# your code goes here
 
class Solution:
    def sortColors(self, nums):
        low, mid, high = 0, 0, len(nums) - 1
 
        while mid <= high:
            if nums[mid] == 0:
                nums[low], nums[mid] = nums[mid], nums[low]
                low += 1
                mid += 1
            elif nums[mid] == 1:
                mid += 1
            else:  # nums[mid] == 2
                nums[mid], nums[high] = nums[high], nums[mid]
                high -= 1
 

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