Mark 一個類...一個很簡單的二叉查找樹...

#ifndef BINARYSEARCHTREE_H_INCLUDED
#define BINARYSEARCHTREE_H_INCLUDED  
  
/** 
 * File BinarySearchTree.h 
 * the Header file of binary search tree 
 **/  
#include <stack>  
#include <utility>  
  
using namespace std;  
  
template <typename Entry>  
class BinarySearchTree  
{  
public:  
    BinarySearchTree()  
    {  
        this->root = NULL;  
        this->size = 0;  
    }  
  
    BinarySearchTree(const BinarySearchTree& rhs)  
    {  
        this->root = NULL;  
        this->size = rhs.size;  
        root = clone(rhs.root);  
    }  
  
    ~BinarySearchTree()  
    {  
        clear();  
    }  
  
    const BinarySearchTree& operator=(const BinarySearchTree& rhs)  
    {  
        if (this != &rhs)  
        {  
            clear();  
            root = clone(rhs.root);  
            this->size = rhs.size;  
        }  
        return *this;  
    }  
  
    /** 
     * return the size of the binary search tree 
     */  
    int getSize()  
    {  
        return this->size;  
    }  
  
    /** 
     * if the tree is empty, return tree 
     **/  
    bool empty() const  
    {  
        return root == NULL;  
    }  
  
    /** 
     * insert x into the tree 
     * if x is alrealdy in the tree, then the method is undefined 
     **/  
    void insert(const Entry& x)  
    {  
        insert(root, x);  
    }  
  
    /** 
     * remove x from the tree 
     * if the x is not in the tree, then the method is undefined 
     **/  
    void remove(const Entry& x)  
    {  
        search_remove(root, x);  
    }  
  
    /** 
     * clear all nodes in the tree 
     **/  
    void clear()  
    {  
        clear(root);  
    }  
  
    /** 
     * search x in the tree 
     * if x is not in the tree, return -1, else return 1 
     **/  
    int search(Entry x)  
    {  
        BinaryNode* node = recursiveSearch(root, x);  
        if (node != NULL)  
            return 0;  
        else if (node == NULL)  
        {  
            return -1;  
        }  
        return 0;  
    }  
  
    /** 
     * preorder traversal 
     **/  
    void preorder(void(*visit)(Entry& ))  
    {  
        recursivePreorder(root, visit);  
    }  
  
    /** 
     * inorder traversal 
     **/  
    void inorder(void (*visit)(Entry& ))  
    {  
        recursiveInorder(root, visit);  
    }  
  
    /** 
     * inorder traversal 
     */  
    void postorder(void (*visit)(Entry& ))  
    {  
        recursivePostorder(root, visit);  
    }  
  
    /** 
     * preorder not recursive 
     **/  
    void NRpreorder(void (*visit)(Entry& ))  
    {  
        NRpreorder(root, visit);  
    }  
  
    /** 
     * inorder not recursive 
     **/  
    void NRinorder(void (*visit)(Entry& ))  
    {  
        NRinorder(root, visit);  
    }  
  
    /**  
     * postorder not recursive 
     **/  
    void NRpostorder(void (*visit)(Entry& ))  
    {  
        NRpostorder(root, visit);  
    }  
  
private:  
    struct BinaryNode  
    {  
        Entry data;  
        BinaryNode* left;  
        BinaryNode* right;  
  
        BinaryNode()  
        {  
            left = NULL;  
            right = NULL;  
        }  
  
        BinaryNode(const Entry& data, BinaryNode* left = NULL, BinaryNode* right = NULL)  
        {  
            this->data = data;  
            this->left = NULL;  
            this->right = NULL;  
        }  
    };  
  
    BinaryNode* root;  
    int size;  
  
    BinaryNode* recursiveSearch(BinaryNode* & subRoot, Entry& x)  
    {  
        if (subRoot == NULL || subRoot->data == x)  
            return subRoot;  
        if (x > subRoot->data)  
            return recursiveSearch(subRoot->right, x);  
        else if (x < subRoot->data)  
            return recursiveSearch(subRoot->left, x);  
    }  
  
    void insert(BinaryNode* & subRoot, const Entry& x)  
    {  
        if (subRoot == NULL)  
        {  
            subRoot = new BinaryNode(x);  
            size++;  
        }  
        else if (x > subRoot->data)  
        {  
            insert(subRoot->right, x);  
        }  
        else if (x < subRoot->data)  
        {  
            insert(subRoot->left, x);  
        }  
        else  
        {  
            ; // do nothing, the entry is duplicate;  
        }  
    }  
  
    void search_remove(BinaryNode* & subRoot, const Entry& x)  
    {  
        if (subRoot == NULL)  
            return; // the remove value is not found  
        if (x > subRoot->data)  
            search_remove(subRoot->right, x);  
        else if (x < subRoot->data)  
            search_remove(subRoot->left, x);  
        else if (x == subRoot->data)  
            remove(subRoot, x);  
    }  
  
    void remove(BinaryNode* & subRoot, const Entry& x)  
    {  
        if (subRoot == NULL)  
            return; // the value x is not found  
  
        BinaryNode* toDelete = subRoot;  
  
        if (subRoot->right == NULL)  
        {  
            subRoot = subRoot->left;  
        }  
        else if (subRoot->left == NULL)  
        {  
            subRoot = subRoot->right;  
        }  
        else  
        {  
            toDelete = subRoot->left;  
            BinaryNode* parent = subRoot;  
            while (toDelete->right != NULL)  
            {  
                parent = toDelete;  
                toDelete = toDelete->right;  
            }  
  
            subRoot->data = toDelete->data;  
  
            if (parent == subRoot)  
            {  
                subRoot->left = toDelete->left;  
            }  
            else  
            {  
                parent->right = toDelete->left;  
            }  
        }  
        delete toDelete;  
        toDelete = NULL;  
        size--;  
    }  
  
    void clear(BinaryNode* & subRoot)  
    {  
  
        if (subRoot != NULL)  
        {  
            // 一直爬到樹的底部進行刪除  
            clear(subRoot->left);  
            clear(subRoot->right);  
            delete subRoot;  
        }  
        subRoot = NULL;  
    }  
  
    // copy the whole tree  
    BinaryNode* clone(BinaryNode* subRoot) const  
    {  
        if (subRoot == NULL)  
            return NULL;  
        else  
        {  
            return new BinaryNode(subRoot->data, clone(subRoot->left), clone(subRoot->right));  
        }  
    }  
  
    BinaryNode* findMin(BinaryNode* subRoot) const  
    {  
        if (subRoot == NULL)  
            return NULL;  
        else if (subRoot->left == NULL)  
            return subRoot;  
        else  
            return findMin(subRoot->left);  
    }  
  
    BinaryNode* findMax(BinaryNode* subRoot) const  
    {  
        if (subRoot != NULL)  
        {  
            while (subRoot->right != NULL)  
                subRoot = subRoot->right;  
        }  
        return subRoot;  
    }  
  
    void recursivePreorder(BinaryNode* subRoot, void (*visit)(Entry& ))  
    {  
        if (subRoot != NULL)  
        {  
            (*visit)(subRoot->data);  
            recursivePreorder(subRoot->left, visit);  
            recursivePreorder(subRoot->right, visit);  
        }  
    }  
  
    void recursiveInorder(BinaryNode* subRoot, void (*visit)(Entry& ))  
    {  
        if (subRoot != NULL)  
        {  
            recursiveInorder(subRoot->left, visit);  
            (*visit)(subRoot->data);  
            recursiveInorder(subRoot->right, visit);  
        }  
    }  
  
    void recursivePostorder(BinaryNode* subRoot, void (*visit)(Entry& ))  
    {  
        if (subRoot != NULL)  
        {  
            recursivePostorder(subRoot->left, visit);  
            recursivePostorder(subRoot->right, visit);  
            (*visit)(subRoot->data);  
        }  
    }  
  
  
    void NRpreorder(BinaryNode* subRoot, void (*visit)(Entry& ))  
    {  
        stack<BinaryNode* > nodeStack;  
  
        while (subRoot != NULL || !nodeStack.empty())  
        {  
            if (subRoot != NULL)  
            {  
                (*visit)(subRoot->data);  
                nodeStack.push(subRoot);  
                subRoot = subRoot->next;  
            }  
            else  
            {  
                BinaryNode* topNode = nodeStack.top();  
                nodeStack.pop();  
                subRoot = topNode->right;  
            }  
        }  
    }  
  
    void NRinorder(BinaryNode* subRoot, void (*visit)(Entry& ))  
    {  
        stack<BinaryNode* > nodeStack;  
  
        while (subRoot != NULL || !nodeStack.empty())     
        {  
            if (subRoot != NULL)  
            {  
                nodeStack.push(subRoot);  
                subRoot = subRoot->left;  
            }  
            else  
            {  
                BinaryNode* topNode = nodeStack.top();  
                nodeStack.pop();  
                (*visit)(topNode);  
                subRoot = topNode->right;  
            }  
        }  
    }  

	void NRpostorder(BinaryNode* subRoot, void (*visit)(Entry& ))  
    {  
        stack<pair<BinaryNode*, bool> > nodeStack; // node pointer, flag  
  
		while (subRoot != NULL || !nodeStack.empty())
		{
			if (subRoot != NULL)
			{
				nodeStack.push(make_pair(subRoot, false));
				subRoot = subRoot->left;
			}
			else
			{
				pair<BinaryNode*, bool> topPair = nodeStack.top();
				BinaryNode* topNode = topPair.first;
				nodeStack.pop();
				if (topPair.second == true)
				{
					(*visit)(topNode->data);
					//topPair.second = true;
					//nodeStack.pop();
				}
				else
				{
					topPair.second = true;
					nodeStack.push(topPair);
					subRoot = topNode->right;
				}
			}
		}
    }  

};


#endif // BINARYSEARCHTREE_H_INCLUDED