Problem
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:
You must do this in-place without making a copy of the array.
Minimize the total number of operations.
Solution
Two pointers.
One pointer is for the start of 0.
One pointer keeps going forward.
class Solution:
def moveZeros(self, nums):
p1, p2 = 0, 0
for p2 < len(nums):
if nums[p1] != 0:
p1 += 1
elif nums[p2] != 0:
nums[p1], nums[p2] = nums[p2], nums[p1]
p1 += 1
p2 += 1
return nums