Move Zeroes——Two Pointers

Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements.

For example, given nums = [0, 1, 0, 3, 12], after calling your function, nums should be [1, 3, 12, 0, 0].

Note:

1. You must do this in-place without making a copy of the array.
2. Minimize the total number of operations.

class Solution(object):
    def moveZeroes(self, nums):
        """
        :type nums: List[int]
        :rtype: void Do not return anything, modify nums in-place instead.
        """
        start, end = 0, 0
        
        while end < len(nums) and start < len(nums):
            while start < len(nums) and nums[start] != 0: 
                start += 1
            end = start + 1
            while end < len(nums) and nums[end] == 0: 
                end += 1
            if end < len(nums) and start < len(nums):
                nums[start] = nums[end]
                nums[end] = 0