数据结构之二叉树的建立与遍历

已知一个按先序序列输入的字符序列，如abc,,de,g,,f,,,(其中逗号表示空节点)。请建立二叉树并按中序和后序方式遍历二叉树，最后求出叶子节点个数和二叉树深度。

#include<iostream>
#include<queue>
#include <cstdlib>
#include <cstdio>
using namespace std;
typedef struct BiNode
{
	char data;
	struct BiNode *left;
	struct BiNode *right;
}BiNode, *BiTree;
int sum = 0;
void CreateBinaryTree(BiTree &T)//二叉树建立   abc,,de,g,,f,,,
{
	//T = (BiNode*) malloc (sizeof(BiNode));
	T = new BiNode;
	cin >> T->data;
	if(T->data == ',') 
	{
		T = NULL; 
	}
	if(T != NULL)
	{
		CreateBinaryTree(T->left);
		CreateBinaryTree(T->right);
	}
}
void PreOrder(BiTree T)//前序遍历
{
	if(T != NULL)
	{
		cout << T->data;
		PreOrder(T->left);
		PreOrder(T->right);
	}
}
void InOrder(BiTree T)//中序遍历
{
	if(T != NULL)
	{
		InOrder(T->left);
		cout << T->data;
		InOrder(T->right);
	}
}
void PostOrder(BiTree T)//后序遍历
{
	if(T != NULL)
	{
		PostOrder(T->left);
		PostOrder(T->right);
		cout << T->data;
	}
}
void LevOrder(BiTree T)//层次遍历
{
	if(T != NULL)
	{
		BiTree p = T;
		queue<BiTree>que;
		que.push(p);
		while(!que.empty())
		{
			p = que.front();
			cout << p->data;
			que.pop();
			if(p->left != NULL)
			{
				que.push(p->left);
			}
			if(p->right != NULL)
			{
				que.push(p->right);
			}
		}
	}
}
int Size(BiTree T)//计算二叉树节点数
{
	if(T)
	{
		if(T->left == NULL && T->right == NULL)
		{
			sum++;
		}
		Size(T->left);
		Size(T->right);
	}
	return sum;
}
int Deep(BiTree T)//计算二叉树深度
{
	int m, n;
	if(T == NULL) return 0;
	m = Deep(T->left);
	n = Deep(T->right);
	if(m > n) return m + 1;
	else return n + 1;
}
int main(void)
{
	BiTree T;
	CreateBinaryTree(T);

	cout << "前序遍历结果为：" << endl;
	PreOrder(T);
	cout << endl << endl;

	cout << "中序遍历结果为：" << endl;
	InOrder(T);
	cout << endl << endl;

	cout << "后序遍历结果为：" << endl;
	PostOrder(T);
	cout << endl << endl;

	cout<<"层次遍历结果为："<<endl;
	LevOrder(T);
	cout << endl << endl;

	cout << "二叉树叶节点个数为：" << Size(T)<<endl;
	cout << "二叉树深度数为：" << Deep(T) << endl;
	system("pause");
	return 0;
}