binarytree.h

重言式是当所有逻辑变元取遍所有值时都为真的表达式。这个程序是用来对重言式进行判别的！还可以吧！牛人别见笑！

#ifndef BinaryTree_H
#define BinaryTree_H

#include "BiTreeNode.h"

template<typename ElemType>
class BinaryTree
{
public:
	typedef bool (*VisitFunc)(BiTreeNode<ElemType> *pNode);

public:
	// class constructor
	BinaryTree()
	{
		m_pRootNode = NULL;
	}	
	
	// class destructor
	~BinaryTree()
	{
	}
	
	bool IsEmpty()
	{
		return m_pRootNode == NULL;
	}
	
	bool Root(ElemType& root) const
	{
		if (!IsEmpty()) 
		{
			root = m_pRootNode->Element();
			return true;
		}
		else
		{
			return false;
		}
	}
	
	void MakeTree(ElemType const& elem, BinaryTree<ElemType>* left = NULL, BinaryTree<ElemType>* right = NULL)
	{
		m_pRootNode = new BiTreeNode<ElemType>(elem, left, right);
		left->Root(NULL);
		right->Root(NULL);
	}
	
	void BreakTree(ElemType& elem, BinaryTree<ElemType>& left, BinaryTree<ElemType>& right)
	{
		if (m_pRootNode == NULL) 
			return;

		elem = m_pRootNode->Element();
		left->Root(m_pRootNode->Left());
		right->Root(m_pRootNode->Right());
	}

	void PreOrder(VisitFunc visit)
	{
		preOrder(visit, m_pRootNode);
	}

	void InOrder(VisitFunc visit)
	{
		inOrder(Visit,m_pRootNode);
	}


	void PostOrder(VisitFunc visit)
	{
		postOrder(Visit,m_pRootNode);
	}
	
protected:

	void preOrder(VisitFunc visit, BiTreeNode<ElemType>* pNode)
	{
		if (pNode != NULL)
		{
			if (visit != NULL && !visit(pNode))
				return false;
				
			preOrder(pNode->Left());
			preOrder(pNode->Right());
		}
	}

	bool inOrder(BiTreeNode<ElemType>* pNode, VisitFunc pfnVisit)
	{
		if (pNode != NULL)
		{
			preOrder(pNode->Left());

			if (visit != NULL && !visit(pNode))
				return false;

			preOrder(pNode->Right());
		}            
	}

	// Recurse in tree
	bool postOrder(BiTreeNode<ElemType>* pNode, VisitFunc pfnVisit)
	{
		if (pNode != NULL)
		{
			preOrder(pNode->Left());
			preOrder(pNode->Right());
			
			if (visit != NULL && !visit(pNode))
				return false;
		}             
	}
	
private:
	BiTreeNode<ElemType>* m_pRootNode;
};

#endif // BinaryTree_H