Leetcode 75. Sort Colors

class Solution:
    def sortColors(self, nums: List[int]) -> None:
        """
        Do not return anything, modify nums in-place instead.
        """
        l, r = 0, len(nums) - 1
        j = 0
        while j < len(nums):
            if nums[j] == 0 and j >= l:
                nums[l], nums[j] = nums[j], nums[l]
                l += 1
            elif nums[j] == 2 and j <= r:
                nums[r], nums[j] = nums[j], nums[r]
                r -= 1
            else:
                j += 1
            if not l<r:
                break