二叉树：C++实现

Posted 2021-04-09 Action and Think

 1#ifndef _二叉树_H
 2#define _二叉树_H
 3#include<iostream>
 4#include<queue>
 5template<class T> class BinaryTree;
 6template<class T> 
 7class TreeNode
 8{
 9public:
 10    TreeNode()
 11    {
 12        leftChild=NULL;
 13        rightChild = NULL;
 14    }
 15    T data;
 16    TreeNode<T> *leftChild;
 17    TreeNode<T> *rightChild;
 18};
 19template<class T> 
 20class BinaryTree
 21{
 22public:
 23    //二叉树进行的操作
 24    void InOrder();
 25    void InOrder(TreeNode<T>* currentNode);
 26    void PreOrder();
 27    void PreOrder(TreeNode<T>* currentNode);
 28    void PostOrder();
 29    void PostOrder(TreeNode<T>* currentNode);
 30    void LevelOrder();
 31    void Visit(TreeNode<T>* currentNode);
 32public:
 33    TreeNode<T> *root;
 34};
 35template<class T>
 36void BinaryTree<T>::LevelOrder()//层序遍历
 37{
 38    std::queue<TreeNode<T>*> q;
 39    TreeNode<T>* currentNode = root;
 40    while(currentNode)
 41    {
 42        Visit(currentNode);
 43        if(currentNode->leftChild) q.push(currentNode->leftChild);
 44        if(currentNode->rightChild) q.push(currentNode->rightChild);
 45        if(q.empty()) return ;
 46        currentNode = q.front();
 47        q.pop();
 48    }
 49}
 50template<class T>
 51void BinaryTree<T>::Visit(TreeNode<T>* currentNode)
 52{
 53    std::cout << currentNode->data;
 54}
 55template<class T>
 56void BinaryTree<T>::InOrder()//中序遍历
 57{
 58    InOrder(root);
 59}
 60template<class T>
 61void BinaryTree<T>::InOrder(TreeNode<T>* currentNode)
 62{
 63    if(currentNode)
 64    {
 65        InOrder(currentNode->leftChild);
 66        Visit(currentNode);//显示当前节点
 67        InOrder(currentNode->rightChild);
 68    }
 69}
 70template<class T>
 71void BinaryTree<T>::PreOrder()//前序遍历
 72{
 73    PreOrder(root);
 74}
 75template<class T>
 76void BinaryTree<T>::PreOrder(TreeNode<T>* currentNode)
 77{
 78    if(currentNode)
 79    {
 80        Visit(currentNode);
 81        PreOrder(currentNode->leftChild);
 82        PreOrder(currentNode->rightChild);
 83    }
 84}
 85template<class T>
 86void BinaryTree<T>::PostOrder()//后序遍历
 87{
 88    PostOrder(root);
 89}
 90template<class T>
 91void BinaryTree<T>::PostOrder(TreeNode<T>* currentNode)
 92{
 93    if(currentNode)
 94    {
 95        PostOrder(currentNode->leftChild);
 96        PostOrder(currentNode->rightChild);
 97        Visit(currentNode);
 98    }
 99}
100#endif

二叉树

 1#include<iostream>
 2#include"二叉树.h"
 3using namespace std;
 4int main()
 5{
 6    BinaryTree<char> tree;
 7    TreeNode<char> 加,减,乘,除,a,b,c,d,e;
 8    加.data = '+';
 9    减.data = '-';
10    乘.data ='*';
11    除.data='/';
12    a.data = 'A';
13    b.data = 'B';
14    c.data = 'C';
15    d.data = 'D';
16    e.data = 'E';
17    tree.root = &加;
18    加.leftChild = &减;
19    加.rightChild = &e;
20    减.leftChild = &乘;
21    减.rightChild = &d;
22    乘.leftChild = &除;
23    乘.rightChild = &c;
24    除.leftChild = &a;
25    除.rightChild = &b;
26    cout<<"中序遍历："<<endl;
27    tree.InOrder();
28    cout << endl;
29    cout<<"前序遍历："<<endl;
30    tree.PreOrder();
31    cout << endl;
32    cout<<"后序遍历："<<endl;
33    tree.PostOrder();
34    cout << endl;
35    cout<<"层序遍历："<<endl;
36    tree.LevelOrder();
37    return 0;
38}