namespace Lesson9_顺序存储和链式存储练习
{
    class LinkNode<T>
    {
        public T value;
        public LinkNode<T> nextNode;
        public LinkNode<T> frontNode;
        public LinkNode(T value)
        {
            this.value = value;
            nextNode = null;
            frontNode = null;
        }
    }
    class LinkList<T>
    {
        private LinkNode<T> head;
        private LinkNode<T> tail;
        private int count;
        public LinkList()
        {
            count = 0;
            head = null;
            tail = null;
        }
        public LinkNode<T> Head
        {
            get
            {
                return head;
            }
        }
        public LinkNode<T> Tail
        {
            get
            {
                return tail;
            }
        }
        public int Count
        {
            get
            {
                return count;
            }
        }
        public void Add(T value)
        {
            LinkNode<T> node = new LinkNode<T>(value);
            if (head == null)
            {
                head = node;
                tail = node;
                Console.WriteLine("空，已加节点并赋值");
            }
            else
            {
                tail.nextNode = node;
                tail.nextNode.frontNode = tail;
                tail = node;
                tail.nextNode = null;
                Console.WriteLine("添加尾部节点");
            }
            ++count;
        }
        public void PrintAllNodesFront()
        {
            if (head == null)
            {
                Console.WriteLine("链表为空");
                return;
            }
            LinkNode<T> node = head;
            while (node != null)
            {
                Console.Write(node.value + " ");
                node = node.nextNode;
            }
        }
        public void PrintAllNodesLast()
        {
            if (head == null)
            {
                Console.WriteLine("链表为空");
                return;
            }
            LinkNode<T> node = tail;
            while (node != null)
            {
                Console.Write(node.value + " ");
                node = node.frontNode;
            }
        }
        public void RemoveAt(int index)
        {
            if (index < 0 || index >= count)
            {
                Console.WriteLine($"目前只有{count}个node,输入无效");
                return;
            }
            int tempCount = 0;
            LinkNode<T> tempNode = head;
            while (true)
            {
                if (tempCount == index)
                {
                    //找到节点
                    if (tempNode.frontNode != null)
                    {
                        tempNode.frontNode.nextNode = tempNode.nextNode;
                    }
                    if (tempNode.nextNode != null)
                    {
                        tempNode.nextNode.frontNode = tempNode.frontNode;
                    }
                    if (index == 0)
                    {
                        head = tempNode.nextNode;
                    }else if (index == count - 1)
                    {
                        tail = tail.frontNode;
                    }

                    count--;
                    break;
                }
                tempNode = tempNode.nextNode;
                tempCount++;
            }
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            LinkList<int> list = new LinkList<int>();
            list.Add(1);
            list.Add(2);
            list.Add(3);
            list.Add(4);

            Console.WriteLine("Node数量:");
            Console.WriteLine(list.Count);
            
            Console.WriteLine("-------------------");

            Console.WriteLine("反向遍历");
            list.PrintAllNodesLast();

            Console.WriteLine();
            Console.WriteLine("-------------------");

            Console.WriteLine("正向遍历");
            list.PrintAllNodesFront();//正向遍历

            Console.WriteLine();
            Console.WriteLine("-------------------");

            Console.WriteLine("删除后正向遍历");
            list.RemoveAt(0);
            list.PrintAllNodesFront();//正向遍历

            Console.WriteLine();
            Console.WriteLine("-------------------");

            Console.WriteLine("删除后反向遍历");
            list.RemoveAt(1);
            list.PrintAllNodesFront();//正向遍历

            Console.WriteLine();
            Console.WriteLine("-------------------");
        }
    }
}