MoveZeroes.java

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.

 

Example 1:

Input: nums = [0,1,0,3,12]
Output: [1,3,12,0,0]
Example 2:

Input: nums = [0]
Output: [0]
 public class MoveZeros {
    public static void moveZeroes(int[] nums) {
        if (nums == null || nums.length == 0) {
            return;
        }

        int nonZeroPointer = 0;

        // Move all non-zero elements to the front
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] != 0) {
                nums[nonZeroPointer++] = nums[i];
            }
        }

        // Fill the remaining elements with zeros
        for (int i = nonZeroPointer; i < nums.length; i++) {
            nums[i] = 0;
        }
    }

    public static void main(String[] args) {
        int[] nums1 = {0, 1, 0, 3, 12};
        moveZeroes(nums1);
        System.out.println(Arrays.toString(nums1)); // Output: [1, 3, 12, 0, 0]

        int[] nums2 = {0};
        moveZeroes(nums2);
        System.out.println(Arrays.toString(nums2)); // Output: [0]
    }
}