Move Zeroes

Hi everyone!
Today I solved a simple but important array problem — moving all zeroes to the end while keeping the order of other elements same.

Problem
Given an array, move all 0's to the end while maintaining the order of non-zero elements.

Example:
Input: [0, 1, 0, 3, 12]

Output: [1, 3, 12, 0, 0]

My Approach

At first, I thought of creating a new array, but the problem clearly says:
Do it in-place
So I used a pointer-based approach.

Logic
Use a pointer insert to track position for non-zero elements
Traverse the array:
If element is non-zero → place it at insert
Increment insert
After that, fill remaining positions with 0

Code (Python)
from typing import List

class Solution:
def moveZeroes(self, nums: List[int]) -> None:
insert = 0

    for i in range(len(nums)):
        if nums[i] != 0:
            if i != insert:
                nums[insert] = nums[i]
            insert += 1

    for i in range(insert, len(nums)):
        nums[i] = 0

Time & Space Complexity
Time: O(n)
Space: O(1) (in-place)

Key Insight
We don’t need to swap every time — just overwrite non-zero elements and then fill zeros at the end.

What I Learned
In-place problems need careful pointer handling
Avoid unnecessary swaps to optimize performance
Simple logic can still be very efficient

Thanks for reading!
Feel free to share any other approaches or improvements.