经典数据结构之二叉树



二叉树是最为基本和最为重要的树结构，是堆的基础，也是学习树最为常见的入口。也是面试最常见的地方，虽然思路简单，却能在很短时间内考察到大家的功底。严格来说，树结构其实就是复杂的链接形式。

.h文件

#include <cstdio>#include <iostream>#include <cassert>#include <queue>#define NULL 0using std::endl;using std::cout;using std::queue;template<typename T>class CBinaryTree;template<typename T>struct SBinaryNode{friend class CBinaryTree<T>;private:    T m_nData;    SBinaryNode<T>* m_pLeft;SBinaryNode<T>* m_pRight;public:SBinaryNode(T data):    m_nData(data){m_pLeft = NULL;        m_pRight = NULL;};~SBinaryNode() {};};template<typename T>class CBinaryTree{typedef void (*mpAction)(SBinaryNode<T>* pNode);private:// members;    SBinaryNode<T>* m_pRoot;int m_nSize;// private methods;void _mPreOrder( mpAction action, SBinaryNode<T>* pNode );void _mInOrder( mpAction action, SBinaryNode<T>* pNode );void _mPostOrder( mpAction action, SBinaryNode<T>* pNode );void _mLevelOrder( mpAction action, SBinaryNode<T>* pNode );// output the data;    static void _mVisit(SBinaryNode<T>* pNode){cout << pNode-> m_nData << '\t';}// free the node;    static void _mFree(SBinaryNode<T>* pNode){delete pNode;}// figure out the height;size_t _mHeight(SBinaryNode<T>* pNode){if(!pNode)return 0;        size_t hl = _mHeight( pNode->m_pLeft);          size_t hr = _mHeight( pNode->m_pRight);  if(hl > hr)return hl + 1 ;elsereturn hr + 1;}    public:// constructors;CBinaryTree();~CBinaryTree(){_mPostOrder(_mFree, m_pRoot);m_pRoot = NULL;};// methods;void mMakeTree(const T& elem, CBinaryTree<T>& leftTree, CBinaryTree<T>& rightTree);void mBreakTree(T& elem, CBinaryTree<T>& leftTree, CBinaryTree<T>& rightTree);// traverse method;void mPreOrder();void mInOrder();void mPostOrder();void mLevelOrder();    bool mRoot(T& x) const;bool mIsEmpty() const {return (m_pRoot) ? true : false;}size_t mHeight();};template<typename T>CBinaryTree<T>::CBinaryTree():m_pRoot(NULL),m_nSize(0) {}template<typename T>void CBinaryTree<T>::mMakeTree(const T& elem, CBinaryTree<T>& left, CBinaryTree<T>& right){//     m_pRoot = new SBinaryNode<T>(elem);    m_pRoot -> m_pLeft = left.m_pRoot;m_pRoot -> m_pRight = right.m_pRoot;// protect the left.m_pRoot and right.m_pRoot;    left.m_pRoot = right.m_pRoot = NULL;}template<typename T>void CBinaryTree<T>::mBreakTree(T& elem, CBinaryTree<T>& leftTree,CBinaryTree<T>& rightTree){assert(m_pRoot != NULL);// decompose the tree;elem = m_pRoot -> m_nData;    leftTree.m_pRoot = m_pRoot-> m_pLeft;rightTree.m_pRoot = m_pRoot -> m_pRight;delete root;}template<typename T>bool CBinaryTree<T>::mRoot(T& elem) const{if(m_pRoot){elem = m_pRoot -> m_nData;return true;}return false;}template<typename T>void CBinaryTree<T>::_mPreOrder(mpAction action, SBinaryNode<T>* pNode){if(pNode){    action(pNode);_mPreOrder(action, pNode->m_pLeft);_mPreOrder(action, pNode->m_pRight);}}template<typename T>void CBinaryTree<T>::_mInOrder(mpAction action, SBinaryNode<T>* pNode){if(pNode){_mInOrder(action, pNode->m_pLeft);    action(pNode);_mInOrder(action, pNode->m_pRight);}}template<typename T>void CBinaryTree<T>::_mPostOrder(mpAction action, SBinaryNode<T>* pNode){if(pNode){_mPostOrder(action, pNode->m_pLeft);_mPostOrder(action, pNode->m_pRight);    action(pNode);}}template<typename T>void CBinaryTree<T>::_mLevelOrder(mpAction action, SBinaryNode<T>* pNode ){queue<SBinaryNode<T>*> queueTmp;SBinaryNode<T>* pTmpNode = pNode;    queueTmp.push(pTmpNode);while(pTmpNode){action(pTmpNode);if(pTmpNode -> m_pLeft)queueTmp.push(pTmpNode -> m_pLeft);if(pTmpNode -> m_pRight)     queueTmp.push(pTmpNode -> m_pRight);queueTmp.pop();if(queueTmp.empty())break;pTmpNode = queueTmp.front();}}template<typename T>void CBinaryTree<T>::mPreOrder(){_mPreOrder(&_mVisit,m_pRoot);}template<typename T>void CBinaryTree<T>::mInOrder(){_mInOrder(&_mVisit,m_pRoot);}template<typename T>void CBinaryTree<T>::mPostOrder(){_mPostOrder(&_mVisit,m_pRoot);}template<typename T>void CBinaryTree<T>::mLevelOrder(){    _mLevelOrder(&_mVisit,m_pRoot);}template<typename T>size_t CBinaryTree<T>::mHeight() {    return _mHeight(m_pRoot);}

test.cpp

#include <stdlib.h>#include <iostream>#include "BinaryTree.h"int main(){// make a tree tree3 with tree1 as left part, tree2 as right part; treeNULL is a null tree;CBinaryTree<int> treeNULL,tree1,tree2,tree3;tree1.mMakeTree(2,treeNULL,treeNULL);tree2.mMakeTree(3,treeNULL,treeNULL);tree3.mMakeTree(1,tree1,tree2);    cout << "PreOrder" << endl;tree3.mPreOrder();cout << endl;    cout << "InOrder" << endl;tree3.mInOrder();cout << endl;    cout << "PostOrder" << endl;tree3.mPostOrder();cout << endl;cout << "LevelOrder" << endl;tree3.mLevelOrder();cout << endl;cout <<"height\t" <<  tree3.mHeight() << endl;system("pause");return 0;}

output

PreOrder1       2       3InOrder2       1       3PostOrder2       3       1height  2请按任意键继续. . .