标签：level bst ESS main mes end delete div stream
二叉查找树（二叉搜索树、二叉排序树）的创建、增、删、查、改。
main.cpp：
#include <iostream> #include "BinarySearchTree.h" using namespace std; int main() { BinarySearchTree<int> bst{ 5,1,3,5,6,6,8,2,4,8,9,0,3,1,7 }; auto il = { 1,2,3,4,5,6 }; bst.insert(il.begin(), il.end()); cout << "datas: "; bst.show(); cout << endl; cout << "size: " << bst.size() << endl; cout << "level: " << bst.level() << endl << endl; cout << "after erase 6: " << endl; cout << "erased: " << bst.erase(6) << " node(s)" << endl; cout << "datas: "; bst.show(); cout << endl; cout << "size: " << bst.size() << endl; cout << "level: " << bst.level() << endl; return 0; }
BinarySearchTree.h：
#pragma once #ifndef __BINARYSEARCHTREE_H__ #define __BINARYSEARCHTREE_H__ #include <queue> #include <initializer_list> template<typename _Ty> class BinarySearchTree { private: struct Node { _Ty key; Node* left = nullptr; Node* right = nullptr; Node* parent = nullptr; Node(const _Ty& _key) :key(_key) {} }; public: BinarySearchTree() = default; template<typename _Iter> BinarySearchTree(_Iter, _Iter); BinarySearchTree(const std::initializer_list<_Ty>&); BinarySearchTree(const BinarySearchTree<_Ty>&); BinarySearchTree(BinarySearchTree<_Ty>&&) noexcept; ~BinarySearchTree() { clear(root); } void clear() { clear(root); } bool empty() const { return size_n == 0; } size_t size() const { return size_n; } void show() const { show(root); } size_t level() const; void swap(BinarySearchTree<_Ty>&); void insert(const _Ty&); template<typename _Iter> void insert(_Iter, _Iter); size_t erase(const _Ty&); void erase(Node*); Node* find(const _Ty& _key) const { return find(root, _key); } Node* iterative_find(const _Ty& _key) const { return iterative_find(root, _key); } Node* maximum() const { return maximum(root); } Node* minimum() const { return minimum(root); } Node* predecessor() const { return predecessor(root); } Node* successor() const { return successor(root); } private: void copy(Node*); void clear(Node*&); void show(Node*) const; Node* find(Node*, const _Ty&) const; Node* iterative_find(Node*, const _Ty&) const; Node* maximum(Node*) const; Node* minimum(Node*) const; Node* predecessor(Node*) const; Node* successor(Node*) const; private: size_t size_n = 0; Node* root = nullptr; }; template<typename _Ty> template<typename _Iter> BinarySearchTree<_Ty>::BinarySearchTree(_Iter _it1, _Iter _it2) { while (_it1 != _it2) { insert(*_it1); ++_it1; } } template<typename _Ty> BinarySearchTree<_Ty>::BinarySearchTree(const std::initializer_list<_Ty>& _il) { for (const auto& key : _il) insert(key); } template<typename _Ty> BinarySearchTree<_Ty>::BinarySearchTree(const BinarySearchTree<_Ty>& _right) { copy(_right.getRoot()); } template<typename _Ty> BinarySearchTree<_Ty>::BinarySearchTree(BinarySearchTree<_Ty>&& _right) noexcept { root = _right.root; size_n = _right.size_n; _right.root = nullptr; _right.size_n = 0; } template<typename _Ty> size_t BinarySearchTree<_Ty>::level() const { if (root == nullptr) 0; size_t n = 0; std::queue<Node*> nodePointers; nodePointers.push(root); while (!nodePointers.empty()) { Node* levelBegin = nodePointers.front(); Node* levelEnd = nodePointers.back(); Node* cur = levelBegin; while (true) { if (cur->left != nullptr) nodePointers.push(cur->left); if (cur->right != nullptr) nodePointers.push(cur->right); if (cur == levelEnd) break; nodePointers.pop(); cur = nodePointers.front(); } nodePointers.pop(); ++n; } return n; } template<typename _Ty> void BinarySearchTree<_Ty>::copy(Node* _node) { if (_node == nullptr) return; insert(_node->key); copy(_node->left); copy(_node->right); } template<typename _Ty> void BinarySearchTree<_Ty>::clear(Node*& _node) { if (_node == nullptr) return; clear(_node->left); clear(_node->right); delete _node; _node = nullptr; --size_n; } template<typename _Ty> void BinarySearchTree<_Ty>::show(Node* _node) const { if (_node == nullptr) return; show(_node->left); std::cout << _node->key << " "; show(_node->right); } template<typename _Ty> void BinarySearchTree<_Ty>::swap(BinarySearchTree<_Ty>& _right) { std::swap(root, _right->root); std::swap(size_n, _right->size_n); } template<typename _Ty> void BinarySearchTree<_Ty>::insert(const _Ty& _key) { ++size_n; if (root == nullptr) { root = new Node(_key); return; } Node* temp = root; while (true) { if (_key < temp->key && temp->left != nullptr) temp = temp->left; else if (_key < temp->key && temp->left == nullptr) break; else if (_key >= temp->key && temp->right != nullptr) temp = temp->right; else break; } Node* newNode = new Node(_key); newNode->parent = temp; if (_key < temp->key) temp->left = newNode; else temp->right = newNode; } template<typename _Ty> template<typename _Iter> void BinarySearchTree<_Ty>::insert(_Iter _it1, _Iter _it2) { while (_it1 != _it2) { insert(*_it1); ++_it1; } } template<typename _Ty> size_t BinarySearchTree<_Ty>::erase(const _Ty& _key) { size_t n = 0; Node* del = find(_key); while (del != nullptr) { ++n; erase(del); del = find(_key); } return n; } template<typename _Ty> void BinarySearchTree<_Ty>::erase(Node* _node) { if (_node == nullptr) return; if (_node == root) { if (_node->right != nullptr) { Node* min = minimum(_node->right); min->left = _node->left; root = _node->right; } else root = _node->left; root->parent = nullptr; delete _node; return; } Node* par = _node->parent; if (_node->left == nullptr && _node->right == nullptr) { if (par->left == _node) par->left = nullptr; else par->right = nullptr; } else { if (_node->right != nullptr) { if (_node->left != nullptr) { Node* min = minimum(_node->right); min->left = _node->left; } _node->right->parent = par; if (par->left == _node) par->left = _node->right; else par->right = _node->right; } else { if (_node->left != nullptr) _node->left->parent = par; if (par->left == _node) par->left = _node->left; else par->right = _node->left; } } delete _node; --size_n; } template<typename _Ty> typename BinarySearchTree<_Ty>::Node* BinarySearchTree<_Ty>::find(Node* _node, const _Ty& _key) const { if (_node == nullptr || _node->key == _key) return _node; if (_key < _node->key) return find(_node->left, _key); else return find(_node->right, _key); } template<typename _Ty> typename BinarySearchTree<_Ty>::Node* BinarySearchTree<_Ty>::iterative_find(Node* _node, const _Ty& _key) const { while (_node != nullptr && _node->key != _key) { if (_key < _node->key) _node = _node->left; else _node = _node->right; } return _node; } template<typename _Ty> typename BinarySearchTree<_Ty>::Node* BinarySearchTree<_Ty>::maximum(Node* _node) const { if (_node == nullptr) return _node; while (_node->right != nullptr) _node = _node->right; return _node; } template<typename _Ty> typename BinarySearchTree<_Ty>::Node* BinarySearchTree<_Ty>::minimum(Node* _node) const { if (_node == nullptr) return _node; while (_node->left != nullptr) _node = _node->left; return _node; } template<typename _Ty> typename BinarySearchTree<_Ty>::Node* BinarySearchTree<_Ty>::predecessor(Node* _node) const { if (_node->left != nullptr) return maximum(_node->left); Node* par = _node->parent; while ((par != nullptr) && (_node == par->left)) { _node = par; par = par->parent; } return par; } template<typename _Ty> typename BinarySearchTree<_Ty>::Node* BinarySearchTree<_Ty>::successor(Node* _node) const { if (_node->right != nullptr) return minimum(_node->left); Node* par = _node->parent; while ((par != nullptr) && (_node == par->right)) { _node = par; par = par->parent; } return par; } #endif // !__BINARYSEARCHTREE_H__
标签：level bst ESS main mes end delete div stream
原文地址：https://www.cnblogs.com/teternity/p/BinarySearchTree.html
