二叉树遍历算法实现

  class node<T>
    {
        T data;
        node<T> Lnode, Rnode, Pnode;

        public T Data
        {
            get { return data; }
            set { data = value; }
        }

        public node<T> LNode
        {
            get { return Lnode; }
            set { Lnode = value; }
        }

        public node<T> RNode
        {
            get { return Rnode; }
            set { Rnode = value; }
        }

        public node<T> PNode
        {
            get { return Pnode; }
            set { Pnode = value; }
        }

        public node(){}

        public node(T data)
        {
            this.data = data;
        }

        static void PreOrder<T>(node<T> rootNode)
        {
            Console.WriteLine(rootNode.data);
            PreOrder<T>(rootNode.LNode);
            PreOrder<T>(rootNode.RNode);
        }

        static node<string> BinTree()
        {
            node<string>[] binTree = new node<string>[8];
            //创建结点
            binTree[0] = new node<string>("A");
            binTree[1] = new node<string>("B");
            binTree[2] = new node<string>("C");
            binTree[3] = new node<string>("D");
            binTree[4] = new node<string>("E");
            binTree[5] = new node<string>("F");
            binTree[6] = new node<string>("G");
            binTree[7] = new node<string>("H");
            //使用层次遍历二叉树的思想，构造一个已知的二叉树

            binTree[0].LNode = binTree[1];
            binTree[0].RNode = binTree[2];
            binTree[1].RNode = binTree[3];
            binTree[2].LNode = binTree[4];
            binTree[2].RNode = binTree[5];
            binTree[3].LNode = binTree[6];
            binTree[3].RNode = binTree[7];
            //返回二叉树的根结点
            return binTree[0];
        }

        #region 中序遍历二叉树

        static void MidOrder<T>(node<T> rootNode)
        {
            if (rootNode != null)
            {
                MidOrder<T>(rootNode.LNode);
                Console.WriteLine(rootNode.Data);
                MidOrder<T>(rootNode.RNode);
            }
        } 

        #endregion

        #region 后序遍历二叉树
        static void AfterOrder<T>(node<T> rootNode)
        {
            if (rootNode != null)
            {
                AfterOrder<T>(rootNode.LNode);
                AfterOrder<T>(rootNode.RNode);
                Console.WriteLine(rootNode.Data);
            }

        } 
        #endregion

        #region 层次遍历二叉树

        static void LayerOrder<T>(node<T> rootNode)
        {
            node<T>[] Nodes = new node<T>[20];
            int front = -1;
            int rear = -1;
            if (rootNode != null)
            {
                rear++;
                Nodes[rear] = rootNode;

            }

            while (front != rear)
            {
                front++;
                rootNode = Nodes[front];
                Console.WriteLine(rootNode.Data);
                if (rootNode.LNode != null)
                {
                    rear++;
                    Nodes[rear] = rootNode.LNode;
                }
                if (rootNode.RNode != null)
                {
                    rear++;
                    Nodes[rear] = rootNode.RNode;
                }
            }
        }
        
        #endregion

    }

见原文：http://www.cnblogs.com/xuanfeng/archive/2006/09/20/509897.html