二叉搜索树

#include<iostream>#include<queue>using namespace std;template<class T>struct BinaryTreeNode{    BinaryTreeNode* left;    BinaryTreeNode* right;    T element;    BinaryTreeNode(T ele) :element(ele), left(nullptr), right(nullptr) {}};template<class T>class BinarySearchTree{public:    BinarySearchTree();    BinarySearchTree(const BinarySearchTree<T>& btree);    void LevelTraversal();    BinaryTreeNode<T>* Find(const T& ele) const;    void Insert(const T& ele);    void Delete(const T& ele);    BinaryTreeNode<T>* GetParent(const BinaryTreeNode<T>* node,bool& left) const;    BinaryTreeNode<T>* GetRoot() const    {        return root;    }private:    BinaryTreeNode<T>* root;    BinaryTreeNode<T>* CopyTreeNode(const BinaryTreeNode<T>* node);    void TransParent(BinaryTreeNode<T>* u, BinaryTreeNode<T>* v);    BinaryTreeNode<T>* TreeMinimum( BinaryTreeNode<T>* node) const;    BinaryTreeNode<T>* TreeMaximum(BinaryTreeNode<T>* node) const;};template<class T>BinarySearchTree<T>::BinarySearchTree(){    root = nullptr;}template<class T>BinarySearchTree<T>::BinarySearchTree(const BinarySearchTree<T>& btree){    if (btree.root == nullptr)    {        root = nullptr;        return;    }    root = new BinaryTreeNode<T>(btree.root->element);    root->left = CopyTreeNode(btree.root->left);    root->right = CopyTreeNode(btree.root->right);}template<class T>BinaryTreeNode<T>* BinarySearchTree<T>::CopyTreeNode(const BinaryTreeNode<T>* node){    if (node == nullptr)    {        return nullptr;    }    BinaryTreeNode<T>* t_node = new BinaryTreeNode<T>(node->element);    t_node->left = CopyTreeNode(node->left);    t_node->right = CopyTreeNode(node->right);    return t_node;}template<class T>BinaryTreeNode<T>* BinarySearchTree<T>::Find(const T& ele) const{    BinaryTreeNode<T>* node = root;    while (node != nullptr)    {        if (node->element == ele)        {            return node;        }        else if (node->element > ele)        {            node = node->left;        }        else        {            node = node->right;        }    }    return nullptr;}template<class T>BinaryTreeNode<T>* BinarySearchTree<T>::GetParent(const BinaryTreeNode<T>* node,bool& left) const{    BinaryTreeNode<T>* temp = root;    BinaryTreeNode<T>* parent = root;    if (node == root)    {        return nullptr;    }    while (temp != node)    {        parent = temp;        if(temp->element > node->element)        {            temp = temp->left;        }        else        {            temp = temp->right;        }    }    if (parent->left == node)    {        left = true;    }    else if (parent->right == node)    {        left = false;    }    return parent;}template <class T>BinaryTreeNode<T>* BinarySearchTree<T>::TreeMinimum(BinaryTreeNode<T>* node) const{    BinaryTreeNode<T>* temp = node;    while (temp->left != nullptr)    {        temp = temp->left;    }    return temp;}template<class T>BinaryTreeNode<T>* BinarySearchTree<T>::TreeMaximum(BinaryTreeNode<T>* node) const{    BinaryTreeNode<T>* temp = node;    while (node->right != nullptr)    {        node = node->right;    }    return temp;}template<class T>void BinarySearchTree<T>::LevelTraversal(){    queue<BinaryTreeNode<T>*> que;    que.push(root);    int cur_level_size = 1;    int next_level_size = 0;    while (!que.empty())    {        BinaryTreeNode<T>* cur = que.front();        cout << cur->element << "  ";        que.pop();        cur_level_size--;        if (cur->left != nullptr)        {            que.push(cur->left);            next_level_size++;        }        if (cur->right != nullptr)        {            que.push(cur->right);            next_level_size++;        }        if (cur_level_size == 0)        {            cur_level_size = next_level_size;            next_level_size = 0;            cout << endl;        }    }}template< class T>void BinarySearchTree<T>::Insert(const T& ele){    BinaryTreeNode<T>* node = root;    BinaryTreeNode<T>* parent = root;    if (root == nullptr)    {        root = new BinaryTreeNode<T>(ele);        return;    }    while (node != nullptr)    {        parent = node;        if (node->element > ele)        {                       node = node->left;        }        else        {            node = node->right;        }    }    node = new BinaryTreeNode<T>(ele);    if (ele < parent->element)    {        parent->left = node;    }    else    {        parent->right = node;    }}template<class T>void BinarySearchTree<T>::TransParent(BinaryTreeNode<T>* u, BinaryTreeNode<T>* v){    if (u == root)    {        v = root;        return;    }    bool left;    BinaryTreeNode<T>* parent = GetParent(u, left);    if (left)    {        parent->left = v;    }    else    {        parent->right = v;    }}template<class T>void BinarySearchTree<T>::Delete(const T& ele){    bool node_left;    BinaryTreeNode<T>* node = Find(ele);    BinaryTreeNode<T>* parent = GetParent(node,node_left);    cout << node->element << endl;    cout << parent->element << endl;    if (node->right == nullptr)    {        TransParent(node, node->left);    }    else if (node->left == nullptr)    {        TransParent(node, node->right);    }    else    {        bool replace_left;        BinaryTreeNode<T>* replace = TreeMinimum(node->right);        cout << replace->element << endl;        BinaryTreeNode<T>* replace_parent =GetParent(replace,replace_left);        cout << replace_parent->element << endl;        if (replace_parent != node)        {            TransParent(replace, replace->right);            replace->right = node->right;        }        replace->left = node->left;        if (node_left)        {            parent->left = replace;        }        else        {            parent->right = replace;        }    }   }int main(){    BinarySearchTree<int> btree;    btree.Insert(5);    for (int i = 0; i < 5; i++)    {        btree.Insert(i);    }    for (int i = 6; i < 10; i++)    {        btree.Insert(i);    }    btree.Delete(7);    btree.LevelTraversal();    btree.Insert(7);    btree.LevelTraversal();    btree.Delete(9);    btree.Insert(10);    btree.LevelTraversal();    btree.Insert(9);    btree.Insert(11);    btree.LevelTraversal();    btree.Delete(10);    btree.LevelTraversal();    return 0;}