Example 1:

Input: nums = [3,2,2,3], val = 3
Output: 2, nums = [2,2,,]

Example 2:

Input: nums = [0,1,2,2,3,0,4,2], val = 2
Output: 5, nums = [0,1,4,0,3,,,_]

       static void Main(string[] args)
       {
           RemoveElement();
       }

       private static void RemoveElement()
       {
           var nums = new int[] { 3, 2, 2, 3,};
           int val = 3;
           int length = RemoveElement(nums, val);
           Console.WriteLine($"新的長度:{length}");
           Console.ReadKey();
       }

       private static int RemoveElement(int[] nums, int val)
       {
           int index = 0;
           for (int i = 0; i < nums.Length; i++)
           {
               if (nums[i] != val)
               {
                   nums[index] = nums[i];
                   index += 1;
               }
           }
           return index;
       }