Move Zeroes

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.

Solution:

class Solution {
    public void moveZeroes(int[] nums) {
        int end = 0;
        for (int i = 0; i < nums.length; i ++) {
            if (nums[i] != 0) {
                swap(nums, end ++, i);
            }
        }
    }
    
    private void swap(int[] arr, int x, int y) {
        int temp = arr[x];
        arr[x] = arr[y];
        arr[y] = temp;
    }
}