二叉树的C++实现

这是去年的内容，之前放在github的一个被遗忘的reporsity里面，今天看到了就拿出来

#include<iostream>
#include<string>
using namespace std;
/*
question#2:The creation of BinaryTree
goal:
1.建立二叉树（通过先序序列作为输入）
2.实现中序遍历和层序遍历、元素查找
3.实现、解释
*/
/*先定义队列，以实现二叉树的层序遍历
使用链队列，以达到不预先定义队列大小的效果*/
template <typename Type>class LinkQueue;
template <typename Type>
class LinkQueueNode {
	friend class LinkQueue<Type>;
public:
	LinkQueueNode(Type &e, LinkQueueNode<Type>*p = NULL) :elem(e), next(p) {};
private:
	Type elem;
	LinkQueueNode<Type>*next;
};
template<typename Type>
class LinkQueue {
public:
	LinkQueue() :front(NULL), rear(NULL) {};
	~LinkQueue();
	int IsEmpty()const { return front == NULL; };
	void LinkQueueClear();
	int LinkQueueLength()const;
	Type GetFront();
	void InQueue(Type&e);
	Type OutQueue();
private:
	LinkQueueNode<Type>*front, *rear;
};
template <typename Type>
LinkQueue<Type>::~LinkQueue() {
	LinkQueueNode<Type>*p;
	while (front != NULL) {
		p = front;
		front = front->next;
		delete p;
	}
};
template <typename Type>
void LinkQueue<Type>::InQueue(Type &e) {
	if (front == NULL)front = rear = new LinkQueueNode<Type>(e, NULL);
	else
		rear = rear->next = new LinkQueueNode<Type>(e, NULL);
};
template <typename Type>
Type LinkQueue<Type>::OutQueue() {
	if (IsEmpty())
	{
		cout << "链队列为空！" << endl;
		exit(0);
	}
	LinkQueueNode<Type>*p = front;
	Type e = p->elem;
	front = front->next;
	if (front == NULL)rear = NULL;
	delete p;
	return e;
};
template <typename Type>
Type LinkQueue<Type>::GetFront() {
	if (IsEmpty()) {
		cout << "链队列为空！" << endl;
		exit(0);
	}
	else
		return front->elem;
};
template <typename Type>
int LinkQueue<Type>::LinkQueueLength()const {
	LinkQueueNode<Type>*p = front;
	int i = 0;
	while (p) {
		i++;
		p = p->next;

	}
	return i;
};
template<typename T>class BinaryTree;
template<typename T>
class BinaryTreeNode {//define the node of binary tree
	friend class BinaryTree<T>;
	//friend class BinarySearchTree<T>;
private:
	T data;
	BinaryTreeNode<T>* left;
	BinaryTreeNode<T>* right;
public:
	BinaryTreeNode();
	BinaryTreeNode<T>(const T&ele) :data(ele) {};
	BinaryTreeNode<T>(const T&ele, BinaryTreeNode<T>*l, BinaryTreeNode<T>*r) :data(ele), left(l), right(r) {};
	~BinaryTreeNode() {};
	T value()const { return data; }
	BinaryTreeNode<T>& operator=(const BinaryTreeNode<T>&Node) { this = Node; };
	BinaryTreeNode<T>*leftchild()const { return left; };
	BinaryTreeNode<T>*rightchild()const { return right; };
	void setLeftchild(BinaryTreeNode<T>*);
	void setRightchild(BinaryTreeNode<T>*);
	void setValue(const T&val);
	bool isLeaf()const;
};
template<typename T>
class BinaryTree {//define the binary tree
protected:
	BinaryTreeNode<T>*root;
public:
	BinaryTree() {
		root = NULL;
	}
	BinaryTree(BinaryTreeNode<T>*r) { root = r; }
	//~BinaryTree() { DeleteBinaryTree(root); };
	//bool isEmpty()const;
	void visit(const T&data) { cout << data << ' '; };
	BinaryTreeNode<T>*&Root() { return root; };
	/*BinaryTreeNode<T>*Parent(BinaryTreeNode<T>*current);
	BinaryTreeNode<T>*LeftSibling(BinaryTreeNode<T>*current);
	BinaryTreeNode<T>*RightSibling(BinaryTreeNode<T>*current);*/
	void CreateTree(const T&data, BinaryTree<T>&leftTree, BinaryTree<T>&rightTree);
	void CreateTree(BinaryTreeNode<T>*&r);
	void DeleteBinaryTree(BinaryTreeNode<T>*root);
	//void PreOrder(BinaryTreeNode<T>*root);
	void InOrder(BinaryTreeNode<T>*root);
	/*void PostOrder(BinaryTreeNode<T>*root);
	void PreOrderWithoutRecusion(BinaryTreeNode<T>*root);
	void InOrderWithoutRecusion(BinaryTreeNode<T>*root);
	void PostOrderWithoutRecusion(BinaryTreeNode<T>*root);*/
	void LevelOrder(BinaryTreeNode<T>*root);
	bool Search(BinaryTreeNode<T>*root,T&data);
};
template<typename T>
/*利用用户输入的先序遍历序列来初始化二叉树*/
void BinaryTree<T>::CreateTree(BinaryTreeNode<T>*& r)
{
	char ch;
	cin >> ch;
	if (ch == '#')r = NULL;
	else {
		r = new BinaryTreeNode<T>(ch);
		CreateTree(r->left);
		CreateTree(r->right);
	}
};
template<typename T>
bool BinaryTree<T>::Search(BinaryTreeNode<T>*root,T &data)
{
/*前序遍历，递归进行元素的搜索*/
	int flag = 0;
	if (root == NULL)
		return 0;
	if (root->data == data)
	{
		flag = 1;
		return flag;
	}
	flag=flag+Search(root->left, data);
	flag=flag+Search(root->right, data);
	return flag;
	
};
template<typename T>
void BinaryTree<T>::InOrder(BinaryTreeNode<T>*root)
{
	/*二叉树的中序遍历*/
	if (root == NULL)return;
	InOrder(root->left);
	visit(root->data);
	InOrder(root->right);
};
template<typename T>
void BinaryTree<T>::LevelOrder(BinaryTreeNode<T>*root)
{
	/*二叉树的层序遍历*/
	LinkQueue<BinaryTreeNode<T>*>tQueue;//链队列，节点类型为二叉树节点指针类型
	BinaryTreeNode<T>*pointer = root;
	if (pointer)tQueue.InQueue(pointer);
	while (!tQueue.IsEmpty()) {
		pointer = tQueue.GetFront();
		tQueue.OutQueue();
		visit(pointer->value());
		if (pointer->leftchild() != NULL)
			tQueue.InQueue(pointer->left);
		if (pointer->rightchild() != NULL)
			tQueue.InQueue(pointer->right);
	}
};
int main()
{
	char te ='A';
	BinaryTree<char> test;//注意，用模板来创建对象时不使用new语句！！！
	//BinaryTreeNode<char>* temp;
	//temp = test.Root();
	test.CreateTree(test.Root());//建立二叉树（通过先序序列作为输入）
	test.InOrder(test.Root());//中序遍历
	test.LevelOrder(test.Root());//层序遍历
	if (test.Search(test.Root(), te))
		cout << "True" << endl;
	else
		cout << "False" << endl;
	return 0;
}