Move Zeroes

LeetCode Q 283 - 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:

• You must do this in-place without making a copy of the array.
• Minimize the total number of operations.

Solution :

Code:

public void moveZeroes(int[] nums) {
	
	if (nums == null || nums.length == 0) return;
	
	int index = 0; // the first zero
	for (int i = 0; i < nums.length; i++) {
		if (nums[i] != 0) {
			swap(nums, i, index);
			index++;
		}
	}
}

private void swap(int[] nums, int i, int j) {
	int temp = nums[i];
	nums[i] = nums[j];
	nums[j] = temp;
}