SLinkedList<int> slist = new SLinkedList<int>();
slist.Append(1);
slist.Append(2);
slist.Append(4);
Console.WriteLine(slist.Print());

SLinkedList<int> slist2 = new SLinkedList<int>();
slist2.Append(1);
slist2.Append(3);
slist2.Append(4);
Console.WriteLine(slist2.Print());

Console.WriteLine("MergeTwoList");
var rslt = slist.MergeTwoList(slist2);
Console.WriteLine(rslt.Print());
 

/// <summary>
/// 合併 2 個有序連結串列
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="source"></param>
/// <param name="source2"></param>
/// <returns></returns>
public static SLinkedList<T> MergeTwoList<T>(this SLinkedList<T> source, SLinkedList<T> source2) where T : IComparable<T>
{
    var temp = new SLinkedList<T>(source);
    temp.SelectionSort();
    var temp2 = new SLinkedList<T>(source2);
    temp2.SelectionSort();
    var node = MergeTwoListImp(temp.Head, temp2.Head);
    var rslt = new SLinkedList<T>();
    while (node != null)
    {
        rslt.Append(node.Data);
        node = node.Next;
    }
    return rslt;
}
static SLinkedListNode<T> MergeTwoListImp<T>(SLinkedListNode<T> node1, SLinkedListNode<T> node2) where T : IComparable<T>
{
    if (node1 == null)
    {
        return node2;
    }
    if (node2 == null)
    {
        return node1;
    }
    if (node1.Data.IsLessThan(node2.Data))
    {
        node1.Next = MergeTwoListImp(node1.Next, node2);
        return node1;
    }
    node2.Next = MergeTwoListImp(node1, node2.Next);
    return node2;
}