LeetCode 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:
-----
1. You must do this in-place without making a copy of the array.
2. Minimize the total number of operations.
*/

namespace Problems.LeetCode.Array.MoveZeroes_283
{
    public class Solution
    {
        /// <summary>
        ///     Moves all zeros to the end of an array.
        ///     Moves non zeros to the left first then fills the rest with zeros.
        ///     Time complexity : O(n)
        ///     Space complexity : O(1)
        /// </summary>
        /// <param name="nums">An array of integers.</param>
        public void MoveZeroes(int[] nums)
        {
            var insertAt = 0;

            for (var i = 0; i < nums.Length; i++)
                if (nums[i] != 0)
                    nums[insertAt++] = nums[i];

            while (insertAt < nums.Length)
                nums[insertAt++] = 0;
        }

        /// <summary>
        ///     Moves all zeros to the end of an array.
        ///     Uses two pointers and swapping.
        ///     Time complexity : O(n)
        ///     Space complexity : O(1)
        /// </summary>
        /// <param name="nums">An array of integers.</param>
        public void MoveZeroes2(int[] nums)
        {
            var insertAt = 0;

            for (var i = 0; i < nums.Length; i++)
            {
                if (nums[i] != 0)
                {
                    var temp = nums[insertAt];
                    nums[insertAt++] = nums[i];
                    nums[i] = temp;
                }
            }
        }
    }
}