Move Zeroes

Leetcode link is here

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

Note that you must do this in-place without making a copy of the array.

Java

This is the solution I made a few months ago when I was fiddling around leetcode

class Solution {
    public void moveZeroes(int[] nums) 
    {
        ArrayList<Integer> n = new ArrayList<Integer>();
        int zeroCount = 0;
        for(int i = 0; i < nums.length; i++)
        {
            if(nums[i] != 0)
                n.add(nums[i]);
            else
                zeroCount++;
        }
        
        for(int i = 0; i < zeroCount; i++)
            n.add(0);
        
        int[] rs = n.stream().mapToInt(i -> i).toArray();
        for(int i = 0; i < rs.length; i++)
            nums[i] = rs[i];
    }
}

And this is the solution I've found yesterday.

class Solution {
    int zeroIndex = 0;
    for(int currentIndex = 0; currentIndex < nums.length; currentIndex++)
    {
        if(nums[currentIndex] != 0)
        {
            int temp = nums[zeroIndex];
            nums[zeroIndex] = nums[currentIndex];
            nums[currentIndex] = temp;
            zeroIndex++;
        }
    }
}

oddly enough there isn't much difference in speed, first solution took 3ms and 39.2MB of memory while the second solution took 2ms and 54.9 MB of memory.