程式碼如下：

//Focus.L carpe diem :)

//BiTree node.h
#ifndef NODE_H_
#define NODE_H_
#define NULL 0

//結點的類
class node{
public:
	char data;   //結點值
	node *lchild, *rchild;  //左孩子，右孩子結點
	node *parent;    //父結點
	//建構函式
	node()
	{
		data = 0;
		lchild = NULL;
		rchild = NULL;
		parent = NULL;
	}
}BiTree;



#endif

   然後就是具體的操作咯。分為二叉樹的初始化，建立二叉樹，先序遍歷，中序遍歷，後序遍歷，層次遍歷，求二叉樹的深度，求二叉樹的結點數，二叉樹的複製。程式碼如下：

//Focus.L carpe diem :)

//BiTree 
#include <iostream>
#include <cstdio>
#include <cstring>
#include "node.h"

using namespace std;

//函式宣告

//二叉樹初始化
node *InitBiTree();
//銷燬二叉樹
void DestroyBiTree(node *&T);
//建立二叉樹
void CreateBiTree(node *&T);
//先序遍歷二叉樹
void PreOrderTraverse(node *T);
//中序遍歷二叉樹
void InOrderTraverse(node *T);
//後序遍歷二叉樹
void PostOrderTraverse(node *T);
//層次遍歷二叉樹
void LevelOrderTraverse(node *T);
int printLevelOrderTraverse(node *T, int level);
//二叉樹的深度
int BiTreeDepth(node *T);
//二叉樹的結點數
int BiTreeNodes(node *T);
//二叉樹的複製
void BiTreeDuplicate(node *T, node *&T1);


//二叉樹初始化
node *InitBiTree()
{
	node *T = new node();
	return T;
}

//node & initBiTree(){
//	node * T = new node();
//	return *T;
//}

//銷燬二叉樹
void DestroyBiTree(node *&T)
{
	if (T->lchild != NULL)
		DestroyBiTree(T->lchild);
	if (T->rchild != NULL)
		DestroyBiTree(T->rchild);
	delete(T);
}

//建立二叉樹
void CreateBiTree(node *&T)
{
	char ch;
	//cout << "please enter the keys:" << endl;
	cin >> ch;
	if (ch == '#')
		T = NULL;
	else
	{
		T = new node();
		T->data = ch;
		CreateBiTree(T->lchild);
		CreateBiTree(T->rchild);
	}
}

//先序遍歷二叉樹
void PreOrderTraverse(node *T)
{
	if (T != NULL)
	{
		cout << T->data;
		PreOrderTraverse(T->lchild);
		PreOrderTraverse(T->rchild);
	}
}

//中序遍歷二叉樹
void InOrderTraverse(node *T)
{
	if (T != NULL)
	{
		InOrderTraverse(T->lchild);
		cout << T->data;
		InOrderTraverse(T->rchild);
	}
}

//後序遍歷二叉樹
void PostOrderTraverse(node *T)
{
	if (T != NULL)
	{
		PostOrderTraverse(T->lchild);
		PostOrderTraverse(T->rchild);
		cout << T->data;
	}
}

//層次遍歷二叉樹演算法
int printLevelOrderTraverse(node *T, int level)
{
	if (!T || level < 0)
		return 0;
	if (level == 0)
	{
		cout << T->data << " ";
		return 1;
	}
	return printLevelOrderTraverse(T->lchild, level - 1) + printLevelOrderTraverse(T->rchild, level - 1);
}
void LevelOrderTraverse(node *T)
{
	int i = 0;
	for (i = 0;; i++)
	{
		if (!printLevelOrderTraverse(T, i))
			break;
	}
	cout << endl;
}

//二叉樹的深度
int BiTreeDepth(node *T)
{
	if (T)
	{
		int depl, depr;
		depl = BiTreeDepth(T->lchild);
		depr = BiTreeDepth(T->rchild);
		if (depl >= depr)
			return (depl + 1);
		else
			return (depr + 1);
	}
	return 0;
}

//二叉樹的結點數
int BiTreeNodes(node *T)
{
	if (T)
	{
		int num;
		num = BiTreeNodes(T->lchild);
		num = num + BiTreeNodes(T->rchild);
		num++;
		return num;
	}
	return 0;
}

//二叉樹的複製
void BiTreeDuplicate(node *T, node *&T1)
{
	if (T)
	{
		T1 = new node();
		T1->data = T->data;
		T1->lchild = T1->rchild = NULL;
		BiTreeDuplicate(T->lchild, T1->lchild);
		BiTreeDuplicate(T->rchild, T1->rchild);
	}
}

//選單
void menu()
{
	cout << "*******************Menu********************" << endl;
	cout << "enter the No of the operation you wanna do:" << endl;
	cout << "1.PreOrderTraverse" << "           " << "2.InOrderTraverse" << endl;
	cout << "3.PostOrderTraverse" << "          " << "4.LevelOrderTraverse" << endl;
	cout << "5.Get the depth of the tree" << "  " << "6.Get the numbers of the nodes" << endl;
	cout << "7.Duplicate the tree and print as PreOrderTraverse" << endl;
}


int main()
{
	int n;
	node *BiTree, *BiTree1;
	BiTree = new node();
	cout << "以先序順序輸入二叉樹，#表示空結點，應將二叉樹的所有結點都輸入進去" << endl;
	cout << "Example 想輸入a為父結點，b和c分別為左右孩子結點的時候則輸入: ab##c## " << endl;
	cout << "please enter the keys:" << endl;
	InitBiTree();
	CreateBiTree(BiTree);
	menu();
	cin >> n;
	switch (n)
	{
	case(1):
		cout << "PreOrderTraverse result:" << endl;
		PreOrderTraverse(BiTree);
		cout << endl;
		break;
	case(2) :
		cout << "InOrderTraverse result:" << endl;
		InOrderTraverse(BiTree);
		cout << endl;
		break;
	case(3) :
		cout << "PostOrderTraverse result:" << endl;
		PostOrderTraverse(BiTree);
		cout << endl;
		break;
	case(4) :
		cout << "LevelOrderTraverse result:" << endl;
		LevelOrderTraverse(BiTree);
		cout << endl;
		cout << "(PreOrderTraverse the new BiTree)" << endl;
		break;
	case(5) :
		cout << "Depth of the BiTree is:" << endl;
		cout << BiTreeDepth(BiTree) << endl;
		break;
	case(6) :
		cout << "Numbers of the BiTree Nodes is:" << endl;
		break;
		cout << BiTreeNodes(BiTree) << endl;
	case(7):
		cout << "The Duplicated Tree is:" << endl;
		BiTreeDuplicate(BiTree, BiTree1);
		PreOrderTraverse(BiTree1);
		cout << endl;
		break;
	}
	return 0;
}