C#来完成二叉树的搜索、遍历、及查找

二叉树结点类：

public class Node
    {
        private Node left;
        private Node right;
        private int value;

        public Node(Node left, Node right, int value)
        {
            this.left = left;
            this.right = right;
            this.value = value;
        }

        public Node(int value)
        {
            this.value = value;
        }

        public Node getLeftNode() { return left; }
        public Node getRightNode() { return right; }
        public int getValue() { return value; }


        /// <summary>
        /// 查找某一节点
        /// </summary>
        /// <param name="node">根节点</param>
        /// <param name="value">要查找的值</param>
        /// <returns></returns>
        public Node findNode(Node root, int value)
        {
            if (root == null)
            {
                return null;
            }

            if (root.getValue() == value)
            {
                return root;
            }

            if (value < root.getValue())
            {
                findNode(root.getLeftNode(), value);
            }
            else
            {
                findNode(root.getRightNode(), value);
            }
            return null;
        }

        /// <summary>
        /// 先根遍历
        /// </summary>
        /// <param name="root"></param>
        public static void PreOrder(Node root)
        {
            if (root != null)
            {
                Console.WriteLine(root.getValue());

                PreOrder(root.getLeftNode());
                PreOrder(root.getRightNode());
            }
        }

        /// <summary>
        /// 后根遍历
        /// </summary>
        /// <param name="root"></param>
        public static void AfterOrder(Node root)
        {
            if (root != null)
            {
                AfterOrder(root.getLeftNode());
                AfterOrder(root.getRightNode());
                Console.WriteLine(root.getValue());
            }
        }

        /// <summary>
        /// 中序遍历二叉树
        /// </summary>
        /// <param name="root"></param>
        public static void MidOrder(Node root)
        {
            if (root != null)
            {
                MidOrder(root.getLeftNode());
                Console.WriteLine(root.getValue());
                MidOrder(root.getRightNode());
            }
        }

        public static int leafNodeCount = 0;
        public static void count_leafNode(Node root)
        {
            if (root == null)
            {
                return;
            }
            if (root.getLeftNode() == null && root.getRightNode() == null)
            {
                Console.WriteLine("叶子节点" +  leafNodeCount.ToString() + "的值为:" +   root.getValue());
                leafNodeCount++;
            }
            else
            {
                count_leafNode(root.getLeftNode());
                count_leafNode(root.getRightNode());
            }
        }
    }

为了简便起见，将遍历等相关方法都写在了该节点中。
以下是主程序调用：

public void showMain()
        {
//构建二叉树
            Node[] node=new Node[8];
            node[4] = new Node(5);
            node[5] = new Node(6);
            node[6] = new Node(7);

            node[3] = new Node(node[6], node[7], 3);
            node[2] = new Node(node[4], node[5], 2);
            node[1] = new Node(node[3], null, 2);
            node[0] = new Node(node[1], node[2], 0);

            Console.WriteLine("后根遍历：");
            Node.AfterOrder(node[0]);

            Console.WriteLine("先根遍历:");
            Node.PreOrder(node[0]);

            Console.WriteLine("中根遍历：");
            Node.MidOrder(node[0]);

            Console.WriteLine("共有叶子节点个数为:");
            Node.count_leafNode(node[0]);
            Console.WriteLine(Node.leafNodeCount);

            Console.Read();

        }

【转载；来源：http://www.cnblogs.com/hanxianlong】