Hi, here's your problem today. This problem was recently asked by Facebook:

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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.

Example:
Input: [0,1,0,3,12]
Output: [1,3,12,0,0]
You must do this in-place without making a copy of the array.
Minimize the total number of operations.

Here is a starting point:

<pre lang=py>
class Solution:
  def moveZeros(self, nums):
    # Fill this in.

nums = [0, 0, 0, 2, 0, 1, 3, 4, 0, 0]
Solution().moveZeros(nums)
print(nums)
# [2, 1, 3, 4, 0, 0, 0, 0, 0, 0]
</pre>