This article introduces the binary list representation of a binary tree, and its first, middle and last root traversal.
Take the following binary tree as an example.
#include "stdafx.h"
#include<iostream>
using namespace std;
template<typename T> class tree
{//基于二叉链表的二叉树
struct node
{
T data;
node *lchild;
node *rchild;
};
node *root;
node a, b, c, d, e;
public:
tree()
{//构造函数，一棵静态二叉树
root = &a;
a.data = 'a';
b.data = 'b';
c.data = 'c';
d.data = 'd';
e.data = 'e';
a.lchild = &b;
a.rchild = &c;
c.lchild = &d;
c.rchild = &e;
d.lchild = d.rchild = 0;
e.lchild = e.rchild = 0;
}
void preTraverse(node *root)
{//先根遍历
if (root)
{
cout << root->data << " ";
preTraverse(root->lchild);
preTraverse(root->rchild);
}
}
void preTraverse()
{//先根遍历
preTraverse(root);
}
void InTraverse(node *root)
{//中根遍历
if (root)
{
InTraverse(root->lchild);
cout << root->data << " ";
InTraverse(root->rchild);
}
}
void InTraverse()
{
InTraverse(root);
}
void postTraverse(node *root)
{//后根遍历
if (root)
{
postTraverse(root->lchild);
postTraverse(root->rchild);
cout << root->data << " ";
}
}
void postTraverse()
{
postTraverse(root);
}
};
int main()
{
tree<char> t;
t.preTraverse();
cout << endl;
t.InTraverse();
cout << endl;
t.postTraverse();
cout << endl;
return 0;
}