539. 移动零(两根指针)

class Solution:
    """
    @param nums: an integer array
    @return: nothing
    """
    def moveZeroes(self, nums):
        # write your code here
        #同向型双指针，第一个指针移动，循环赋值，第二个指针移动非0位置，循环给值，最后根据第一个指针，循环赋0
        left, right = 0, 0 
        l = len(nums)
        
        while right < l:
            if nums[right] != 0:
                nums[left] = nums[right]
                left += 1 
            right += 1 
        
        #此时left已经移动到非0的位置，right移动到最右边
        while left < l:
            nums[left] = 0 
            left += 1 
        
        return nums
        

class Solution:
    """
    @param nums: an integer array
    @return: nothing
    """
    def moveZeroes(self, nums):
        # write your code here
        #一个left记录当前非0的位置，right记录走的位置
        left, right = 0, 0
        
        while right < len(nums):
            #right右指针找到非0的个数，left记录下来
            if (nums[right] != 0):
                nums[left], nums[right] = nums[right], nums[left]
                left += 1 
            
            right += 1 
        
        return nums