Move Zeros

https://leetcode.com/problems/move-zeroes/

In-Place

Something to note is that if we want to reduce space complexity, often we'll want to perform our algorithm on the input array instead of creating a new array. This is called in-place.

Answer

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]

Note:

1. You must do this in-place without making a copy of the array.

2. Minimize the total number of operations.

Question

class Solution:
    def moveZeroes(self, nums):
        zero = 0  # records the position of "0"
        for i in range(len(nums)):
            if nums[i] != 0:
                nums[i], nums[zero] = nums[zero], nums[i]
                zero += 1

We swap bubble the 0's up the array in-place.