二叉树
两个值得注意的性质:
1.二叉树是有序树,这个我想了很久不知道为什么,可是为什么二叉树只有三种遍历方式,而不是六种?说明每个形态不同的树都有不同的含义。那完全二叉树和平衡二叉树呢?也是一样的
2.n0=n2+1 推法: n-1=2n2+n1 n=n0+n1+n2
遍历
前 中 后序遍历
cpp
#include <iostream>
#include <stdlib.h>
using namespace std;
typedef struct Node
{
struct Node *left;
struct Node *right;
int data;
} N, Tr;
N *createNode(int data)
{
N *a = (N *)malloc(sizeof(N));
a->left = a->right = NULL;
a->data = data;
return a;
}
void pre(Tr *root)
{
if (root == NULL)
return;
cout
<< root->data << " ";
pre(root->left);
pre(root->right);
}
void In(Tr *root)
{
if (root == NULL)
return;
In(root->left);
cout << root->data << " ";
In(root->right);
}
void aft(Tr *root)
{
if (root == NULL)
return;
aft(root->left);
aft(root->right);
cout << root->data << " ";
}
int main()
{
Tr *root = createNode(3);
root->right = createNode(4);
root->left = createNode(5);
root->left->left = createNode(6);
root->left->right = createNode(7);
root->right->left = createNode(8);
root->right->right = createNode(9);
pre(root);
cout << endl;
In(root);
cout << endl;
aft(root);
cout << endl;
}