数据结构-二叉搜索树

3/8/2017来源:ASP.NET技巧人气:601

#PRagma once
//K/V模型(key/value) 
//运用:英汉互译  

template<typename K, typename V>
struct SearchBinaryTreeNode
{
	SearchBinaryTreeNode<K,V>* _left;
	SearchBinaryTreeNode<K,V>* _right;

	const K _key;  //eg:英译汉
	V _value;

	SearchBinaryTreeNode(const K& key, const V& value)
		: _left(NULL)
		, _right(NULL)
		, _key(key)
		, _value(value)
	{}
};


template<typename K, typename V>
class SearchBinaryTree
{
	typedef SearchBinaryTreeNode<K,V> Node;
public:
	SearchBinaryTree()
		:_root(NULL)
	{}

	~SearchBinaryTree()
	{
		_Destory(_root);
	}

	/*bool Insert(const K& key)
	{
	Node* prev = NULL;
	Node* cur = _root;

	while (cur)
	{
	if (key < cur->_key)
	{
	prev = cur;
	cur = cur->_left;
	}
	else if (key > cur->_key)
	{
	prev = cur;
	cur = cur->_right;
	}
	else
	{
	return false;
	}
	}

	if (_root != NULL)
	{
	if (key < prev->_key)
	{
	prev->_left = new Node(key);
	}
	else
	{
	prev->_right = new Node(key);
	}
	}
	else
	{
	_root = new Node(key);
	}
	return true;
	}*/

	bool Insert(const K& key,const V& value)  //非递归实现插入
	{
		Node* cur = _root;
		Node* node = new Node(key,value);

		while (cur)
		{
			if (key < cur->_key)
			{
				if (cur->_left == NULL)
				{
					cur->_left = node;
					return true;
				}
				else
				{
					cur = cur->_left;
				}
			}
			else if (key > cur->_key)
			{
				if (cur->_right == NULL)
				{
					cur->_right = node;
					return true;
				}
				else
				{
					cur = cur->_right;
				}
			}
			else
			{
				return false;
			}
		}
		_root = node;
		return true;
	}

	bool Remove(const K& key)//非递归实现删除
	{
		Node* parent = NULL;
		Node* cur = _root;

		while (cur)
		{
			if (cur->_key == key)//已找到要删除的节点
			{
				if (cur->_left == NULL)//左为空
				{
					if (cur == _root)
					{
						_root = _root->_right;
					}
					else if (parent->_left == cur)
					{
						parent->_left = cur->_right;
					}
					else if (parent->_right == cur)
					{
						parent->_right = cur->_right;
					}
				}
				else if (cur->_right == NULL)//右为空
				{
					if (cur == _root)//防止斜树删除根节点时parent为NULL导致奔溃
					{
						_root = _root->_left;
					}
					else if (parent->_left == cur)
					{
						parent->_left = cur->_left;
					}
					else if (parent->_right == cur)
					{
						parent->_right = cur->_left;
					}
				}
				else if (cur->_right != NULL && cur->_left != NULL)//左右都不为空
				{
					Node* rightmin = cur->_right;//要删除节点的右子树的最左节点(最小的)
					parent = cur;
					while (rightmin->_left)//找要删除节点的右子树的最左节点(最小的)
					{
						parent = rightmin;
						rightmin = rightmin->_left;
					}
					//替换
					cur->_key = rightmin->_key;
					//假删除
					if (parent->_left == rightmin)
					{
						parent->_left = rightmin->_right;
					}
					else if (parent->_right == rightmin)
					{
						parent->_right = rightmin->_right;
					}
					cur = rightmin;
				}
				break;
			}
			else if (cur->_key < key)
			{
				parent = cur;
				cur = cur->_right;
			}
			else
			{
				parent = cur;
				cur = cur->_left;
			}
		}

		delete cur;
		cur = NULL;
		return true;
	}

	Node* Find(const K& key)  //非递归实现查找
	{
		Node* cur = _root;
		while (cur)
		{
			if (key == cur->_key)
			{
				return cur;
			}
			else if (key < cur->_key)
			{
				cur = cur->_left;
			}
			else
			{
				cur = cur->_right;
			}
		}
		return NULL;
	}

	Node* FindR(const K& key)
	{
		return _FindR(_root, key);
	}

	bool InsertR(const K& key,const V& value)
	{
		return _InsertR(_root, key, value);
	}

	bool RemoveR(const K& key)
	{
		return _RemoveR(_root, key);
	}

	void InOrder()
	{
		_InOrder(_root);
		cout << endl;
	}

	size_t Size()
	{
		return _Size(_root);
	}
protected:

	Node* _FindR(Node* root, const K& key)
	{
		if (root == NULL)
			return NULL;

		if (root->_key > key)
		{
			return _FindR(root->_left, key);
		}
		else if (root->_key < key)
		{
			return _FindR(root->_right, key);
		}
		else
		{
			return root;
		}
	}

	bool _InsertR(Node*& root, const K& key, const V& value) //注意第一个参数加&的道理
	{
		if (root == NULL)
		{
			root = new Node(key, value);
			return true;
		}

		if (root->_key > key)
		{
			return _InsertR(root->_left, key, value);
		}
		else if (root->_key < key)
		{
			return _InsertR(root->_right, key, value);
		}
		else
		{
			return false;
		}
	}

	bool _RemoveR(Node*& root, const K& key)//注意第一个参数加&的道理
	{
		if (root == NULL)
			return false;

		if (root->_key > key)
			return _RemoveR(root->_left, key);
		else if (root->_key < key)
			return _RemoveR(root->_right, key);
		else
		{
			Node* del = NULL;
			if (root->_left == NULL)
			{
				del = root;
				root = root->_right;  //等号左边root表示上一层递归中root的left指针的别名,右边的root代表当前root节点的右指针所指的节点
			}
			else if (root->_right == NULL)
			{
				del = root;
				root = root->_left;
			}
			else
			{
				Node* parent = root;
				Node* newnode = root->_right;  //找root为根其右子树的最左节点

				while (newnode->_left)
				{
					parent = newnode;
					newnode = newnode->_left;
				}

				root->_key = newnode->_key;
				del = newnode;

				if (newnode == parent->_left)
				{
					parent->_left = newnode->_right;
				}
				else if (newnode == parent->_right)
				{
					parent->_right = newnode->_right;
				}
			}

			delete del;
			return true;
		}
	}

	void _InOrder(Node* root)
	{
		if (root == NULL)
		{
			return;
		}

		_InOrder(root->_left);
		cout << root->_key << " ";
		_InOrder(root->_right);
	}

	size_t _Size(Node* _root)
	{
		if (_root == NULL)
			return 0;

		return _Size(_root->_left) + _Size(_root->_right) + 1;
	}

	void _Destory(Node* root)
	{
		if (root == NULL)
			return;

		_Destroy(root->_left);
		_Destroy(root->_right);
		delete root;
	}
protected:
	Node* _root;
};