75. Sort Colors

https://leetcode.com/problems/sort-colors/

Make two pointer for two bounds

zeroBound 从左往右第一个不是0的位置，前面经过swap都是0

twoBound从右往左第一个不是2的位置，后面经过swap都是2

唯一需要注意的是这里的curr在进行zeroBound变换时，需要increment

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