leetcode每日一题：283. 移动零

class Solution:
    def moveZeroes(self, nums: List[int]) -> None:
        """
        Do not return anything, modify nums in-place instead.
        """
        if nums is None or len(nums) < 1:
            return []
        length = len(nums)
        # 借助于内置函数，删除后再在后面添加
        '''
        for i in range(length):
            if nums[i] == 0:
                nums.remove(nums[i])
                nums.append(0)
        return nums 
        '''
        # 类似于快排，零元素与非零元素交换
        '''
        j = 0
        for i in range(length):
            if nums[i]:
                nums[j], nums[i] = nums[i], nums[j]
                j += 1
        return nums 
        '''
        # 双指针法
        j = 0
        for i in range(length):
            if nums[i]:
                nums[j] = nums[i]  # 往左拉
                j += 1
        # 非0元素统计完了，剩下的都是0了
        for i in range(j, length):
            nums[i] = 0
        return nums