代码如下:

#include <iostream>
using namespace std;template <typename K,typename V>
struct BNode
{typedef BNode<K,V> Node;K _key;V _value;Node * _left;Node *_right;BNode(const K & key,const V & value) :_key(key),_value(value), _left(nullptr), _right(nullptr) {}
};template<typename K,typename V>
class BTree
{
public:typedef BNode<K,V> Node;BTree():_root(nullptr){}Node *find(const K & key){Node *cur = _root;while (cur){if (cur->_data == key) return cur;else if (cur->_data > key) cur = cur->_left;else cur = cur->_right;}}bool Insert(const K & key ,const V & value){if (_root == nullptr){_root = new Node(key,value);return true;}Node *cur = _root;Node *parent = nullptr;while (cur){parent = cur;if (cur->_key == key) return false;else if (cur->_key> key) cur = cur->_left;else cur = cur->_right;}cur = new Node(key,value);if (parent->_key > key) parent->_left = cur;else parent->_right = cur;return true;}void inorder(){_inorder(_root);}void _inorder(Node *root){if (root){_inorder(_root->_left);cout << _root->_key << "-->"<<root->_value<<" ";_inorder(_root->_right);}}Node *copy(Node * root){if (root == nullptr) return nullptr;Node *newNode = new Node(root->_key,root->_value);newNode->_left = copy(_root->_left);newNode->_right = copy(_root->_right);return newNode;}BTree(const BTree<K,V> & btree):_root(copy(btree._root)){}void destroy(Node * root){if (root){destroy(_root->_left);destroy(_root->_right);delete root;}}~BTree(){if (_root){destroy(_root);_root = nullptr;}}bool erase(const K & key){Node *cur = _root;Node *parent = nullptr;while (cur){if (cur->_key == key) break;else if (cur->_key > key){parent = cur;cur = cur->_left;}else{parent = cur;cur = cur->_right;}}//判断是否找到了需要删除的结点if (cur == nullptr) return false;//删除结点//1.删除的结点为叶子结点if (cur->_left == nullptr && cur->_right == nullptr){//特殊情况是否根结点if (cur == _root){_root = nullptr;}else{if (parent->_left == cur) parent->_left = nullptr;else parent->_right = nullptr;}delete cur;}//2.要删除的结点存在一个孩子else if (cur->_left == nullptr){if (cur == _root) _root = nullptr;else{if (parent->_left == cur) parent->_left = cur->_right;else parent->_right = cur->_right;}delete cur;}else if (cur->_right == nullptr){if (cur == _root) _root = nullptr;else{if (parent->_left == cur) parent->_left = cur->_left;else parent->_right = cur->_left;}delete cur;}//3.要删除的结点左右孩子都存在else{Node *leftRightMost = cur->_left;parent = cur;while (leftRightMost->_right){parent = leftRightMost;leftRightMost = leftRightMost->_right;}swap(cur->_key, leftRightMost->_key);swap(cur->_value, leftRightMost->_value);if (parent->_left == leftRightMost) parent->_left = leftRightMost->_left;else parent->_right = leftRightMost->_left;delete leftRightMost;}return true;}private:Node * _root;
};