/// <summary>
/// 将两个 Steque 连接。
/// </summary>
/// <param name="s1">第一个 Steque </param>
/// <param name="s2">第二个 Steque （将被删除）</param>
/// <returns></returns>
public static Steque <Item> Catenation(Steque <Item> s1, Steque <Item> s2)
{
if (s1.IsEmpty())
{
s1.first = s2.first;
s1.last = s2.last;
s1.count = s2.count;
}
else
{
s1.last.next = s2.first;
s1.count += s2.count;
}
s2 = null;
return(s1);
}
static void Main(string[] args)
{
var q1 = new Queue <string>();
q1.Enqueue("first");
q1.Enqueue("second");
var q2 = new Queue <string>();
q2.Enqueue("third");
q2.Enqueue("fourth");
q1 = Queue <string> .Catenation(q1, q2);
Console.WriteLine(q1);
var s1 = new Stack <string>();
s1.Push("first");
s1.Push("second");
var s2 = new Stack <string>();
s2.Push("third");
s2.Push("fourth");
s2 = Stack <string> .Catenation(s2, s1);
Console.WriteLine(s2);
var sq1 = new Steque <string>();
sq1.Push("first");
sq1.Enqueue("second");
var sq2 = new Steque <string>();
sq2.Push("third");
sq2.Enqueue("fourth");
sq1 = Steque <string> .Catenation(sq1, sq2);
Console.WriteLine(sq1);
}