如何合并两个排序的链表

这是一个面试问题，但我不知道是否有最好的解决方案。

问题：编写一个函数（用C#或C++）来合并两个已经排序的链表。给定一个数据结构：C++：

class Node
{
public:
int data;
Node* next;
};

C#：

class Node
{
public int data;
public Node next;
};

实现功能：在C++中：

Node* Merge (Node* head1, Node* head2)
{
…
}

在C#中：

Node Merge (Node head1, Node head2)
{
…
}

它接收两个已经排序的链表（按升序），并将它们合并到一个单独排序的链表中（按降序），然后返回新的头。这两个列表可能有具有相同数据（int值）的节点。我们预计结果列表中没有相同的数据。

我的解决方案：

 Node Merge(Node head1, Node head2)
        {
            Node merged = head1;
            // Both lists are empty
            if (head1 == null && head2 == null)
            {
                return null;
            }
            // List 1 is empty
            else if (head1 == null && head2 != null)
            {
                return head2;
            }
            // List 2 is empty
            else if (head2 == null && head1 != null)
            {
                return head1;
            }
            // Both lists are not empty
            else
            {
                Node cursor1 = head1;
                Node cursor2 = head2;
                if (cursor1.next.data > cursor2.data)
                {
                    Node temp = cursor1;
                    cursor1 = cursor2;
                    cursor2 = temp;
                }
// Add all elements from list 2 to list 1
                while (cursor1.next != null && cursor2 != null)
                {
                    if (cursor1.next.data < cursor2.data)
                    {
                        cursor1 = cursor1.next;
                    }
                    else
                    {
                        Node temp1 = cursor1.next;
                        Node temp2 = cursor2.next;
                        cursor1.next = cursor2;
                        cursor2.next = temp1;
                        cursor1 = cursor1.next;
                        cursor2 = temp2;
                    }
                }
                if (cursor1.next == null)
                {
                    cursor1.next = cursor2;
                }
            }
            // Remove duplicates
            head1 = merged;
            while (head1.next != null)
            {
                if (head1.data < head1.next.data)
                {
                    head1 = head1.next;
                }
                else if (head1.data == head1.next.data) 
                {
                    head1.next = head1.next.next;
                }
            }
            return merged;
        }

请给我一些意见，让我知道你的聪明和良好的解决方案。非常感谢。

class Node
{
    public int Data { get; set; }
    public Node Next { get; set; }
}

class NodeEnumerator : IEnumerator<int>
{
    private Node _current_node;
    public NodeEnumerator(Node first) {
        _current_node = new Node { Data = 0, Next = first };
    }
    public int Current {
        get { return _current_node.Data; }
    }
    object IEnumerator.Current {
        get { return Current; }
    }
    public bool MoveNext() {
        if (_current_node == null) {
            return false;
        }
        _current_node = _current_node.Next;
        return _current_node != null;
    }
    public void Reset() {
        throw new NotSupportedException();
    }
    public void Dispose() {
    }
}

class EnumerableNode : IEnumerable<int>
{
    private Node _first;
    public EnumerableNode(Node first) {
        _first = first;
    }
    public IEnumerator<int> GetEnumerator() {
        return new NodeEnumerator(_first);
    }
    IEnumerator IEnumerable.GetEnumerator() {
        return GetEnumerator();
    }
}

class Program
{
    static void Main(string[] args) {
        var list1 = new EnumerableNode(
          new Node { Data = 1, Next =
          new Node { Data = 2, Next =
          new Node { Data = 3, Next = null }}});
        var list2 = new EnumerableNode(
          new Node { Data = 2, Next =
          new Node { Data = 3, Next =
          new Node { Data = 4, Next = null }}});
        var merged = list1.Concat(list2).Distinct();
        Console.WriteLine(String.Join(",", list1));
        Console.WriteLine(String.Join(",", list2));
        Console.WriteLine(String.Join(",", merged));
        Console.ReadLine();
    }
}

1,2,3
2,3,4
1,2,3,4