作者：qaoxiuzcwhyx | 来源：互联网 | 2021-09-05 03:19
二叉树首先要解决构建问题，才能考虑后续的遍历，这里贴出通过先序构建二叉树，同时包含四种二叉树的遍历方法（先序，中序，后序，逐层）
第一、定义BinaryTreeNode 类
#include
#include
#include
using namespace std;
templateclass BinaryTree;
template class BinaryTreeNode {
public:
friend class BinaryTree;
BinaryTreeNode() {
data = NULL;
lChild = rChild = NULL;
}
BinaryTreeNode(T newdata) {
this->data = newdata;
lChild = rChild = NULL;
}
T getData() {
return data;
}
BinaryTreeNode * getLeftNode() {
return lChild;
}
BinaryTreeNode * getRightNode() {
return rChild;
}
T data;
BinaryTreeNode* lChild;
BinaryTreeNode* rChild;
private:
};
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第二、定义BinaryTree 类
template class BinaryTree {
public:
BinaryTreeNode *root;
char* p;
BinaryTree() { root = NULL; }
BinaryTree(T data) {
root = new BinaryTreeNode(data);
root->lChild = NULL;
root->rChild = NULL;
}
~BinaryTree() {
delete root;
}
//构建二叉树并返回
BinaryTreeNode* CreateTree() {
BinaryTreeNode* bt = NULL;
char t;
cin >> t;
if (t == '#')
{
return NULL;
}
else {
int num = t - '0';
bt = new BinaryTreeNode(num);
bt->lChild = CreateTree();
bt->rChild = CreateTree();
}
return bt;
}
//先序构建二叉树
BinaryTreeNode* PreCreateTree() {
BinaryTreeNode* bt = NULL;
if (this->root == NULL)
{
cout <<"请输入根节点（#代表空树）:";
}
else {
cout <<"请输入节点（#代表空树）:";
}
char t;
cin >> t;
if (t == '#')
{
return NULL;
}
else {
int num = t - '0';
bt = new BinaryTreeNode(num);
if (this->root == NULL)
{
this->root = bt;
}
cout <data <<"的左孩子";
bt->lChild = PreCreateTree();
cout <data <<"的右边孩子";
bt->rChild = PreCreateTree();
}
return bt;
}
void preOderTraversal(BinaryTreeNode *bt); //先序遍历
void inOrderTraversal(BinaryTreeNode *bt); //中序遍历
void postOrderTraversal(BinaryTreeNode *bt);//后序遍历
void levelTraversal(BinaryTreeNode *bt); //逐层遍历
private:
};
template
void BinaryTree::preOderTraversal(BinaryTreeNode *bt) {
if (bt)
{
cout <data;
BinaryTree::preOderTraversal(bt->getLeftNode());
BinaryTree::preOderTraversal(bt->getRightNode());
}
}
template
void BinaryTree::inOrderTraversal(BinaryTreeNode *bt) {
if (bt)
{
BinaryTree::inOrderTraversal(bt->getLeftNode());
cout <data;
BinaryTree::inOrderTraversal(bt->getRightNode());
}
}
template
void BinaryTree::postOrderTraversal(BinaryTreeNode *bt) {
if (bt)
{
BinaryTree::postOrderTraversal(bt->getLeftNode());
BinaryTree::postOrderTraversal(bt->getRightNode());
cout <data;
}
}
template
void BinaryTree::levelTraversal(BinaryTreeNode *bt) {
queue*> que;
que.push(bt);
while (!que.empty())
{
BinaryTreeNode* proot = que.front();
que.pop();
cout <data;
if (proot->lChild != NULL)
{
que.push(proot->lChild);//左孩子入队
}
if (proot->rChild != NULL)
{
que.push(proot->rChild);//右孩子入队
}
}
}
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第三、主程序运行
#include "pch.h"
#include
#include "BinaryTree.h"
int main()
{
//场景测试2
BinaryTree btree;
btree.PreCreateTree();//先序构建二叉树
cout <<"先序遍历:";
btree.preOderTraversal(btree.root); cout <
View Code
最终测试运行截图
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