二叉树的创建和遍历C++实现

#ifndef _BiTree
#define _BiTree
#include 
#include 
#include 
using namespace std;
struct BiNode
{
	char data;
	struct BiNode *left,*right;
};

class BiTree
{
public:
	BiTree();
	~BiTree();
	BiNode *getRoot();
	void preOrder(BiNode *root);
	void postOrder(BiNode *root);
	void inOrder(BiNode *root);
	void levelOrder(BiNode *root);
private:
	BiNode *root;
	BiNode *create();
	void Release(BiNode *root);
};

BiTree::BiTree()
{
	this->root=create();
}

BiNode *BiTree::create()
{
	//ifstream cin("E:\\cpp_work\\test\BiTree\\BiTree\\test.txt");
	BiNode *root;
	char ch;
	cout<<"Please input data to build a binary tree:"<>ch;
	if(ch=='#')
		root=NULL;
	else
	{
		root=new BiNode;
		root->data=ch;
		root->left=create();
		root->right=create();
	}
	return root;
}
BiTree::~BiTree()
{
	Release(root);
}
void BiTree::Release(BiNode *root)
{
	if(root!=NULL)
	{
		Release(root->left);
		Release(root->right);
		delete root;
	}
}

BiNode* BiTree::getRoot()
{
	return root;
}

void BiTree::preOrder(BiNode *root)
{
	if(root==NULL)return;
	else
	{
		cout<data;
		preOrder(root->left);
		preOrder(root->right);
	}
};

void BiTree::inOrder(BiNode *root)
{
	if(root==NULL)return;
	else
	{
		inOrder(root->left);
		cout<data;
		inOrder(root->right);
	}
}

void BiTree::postOrder(BiNode *root)
{
	if(root==NULL)return;
	else
	{
		postOrder(root->left);
		postOrder(root->right);
		cout<data;
	}
}
void BiTree::levelOrder(BiNode *root)
{
	queue Q;
	if(root==NULL)
		return;
	Q.push(root);
	while (!Q.empty())
	{
		BiNode *front=Q.front();
		Q.pop();
		cout<data;
		if(front->left!=NULL)
			Q.push(front->left);
		if(front->right!=NULL)
			Q.push(front->right);
	}
}
#endif