数据结构（九）多种遍历、访问伸展树

1、多种遍历

代码:

//多种遍历3
#include<cstdlib>//动态分配内存 
#include<iostream>
#include<stdlib.h>
#include<algorithm>

using namespace std;
//建立节点 
struct NODE
{
	int  value;
	NODE*left;
	NODE*right;
	NODE(int v,NODE *l,NODE *r):value(v),left(NULL),right(NULL)
	{
		left=l;
		right=r;
	}	
} ;
//生成随机函数
int randint(int lower,int upper)
{
	return rand()%(upper-lower+1)+lower;
}
//rand函数 生成随机树 
NODE*generateRandomBST(int lower,int upper) 
{
	NODE*t=nullptr;
	int randomValue;
	if(lower<=upper)
	{
		randomValue=randint(lower,upper);
		t=new NODE(randomValue,generateRandomBST(lower,randomValue-1),generateRandomBST(randomValue+1,upper));
	}
	return t;
}
//1为下限，n为上限 
NODE *generateRandomBST(int n)
{
	return generateRandomBST(1, n);
}
//前序遍历
void preOrder(NODE*root)
{
	if(root!=NULL)
	{
		cout<<root->value<<" ";
		preOrder(root->left);
		preOrder(root->right);
	}
} 
//中序遍历
void inOrder(NODE*root)
{
	if(root!=NULL)
	{
		inOrder(root->left);
		cout<<root->value<<" ";
		inOrder(root->right);
	}
}
//后序遍历
void postOrder(NODE*root)
{
	if(root!=NULL)
	{
		postOrder(root->left);
		postOrder(root->right);
		cout<<root->value<<" ";
	}
} 
//层次遍历
void levelOrder(NODE*t)
{
	int front=0,rear=1;
	NODE *q[1000];
	q[0]=t;
	while(front<rear)
	{
		if(q[front])
		{
			cout<<q[front]->value<<" ";
			q[rear++]=q[front]->left;
			q[rear++]=q[front]->right;
			front++;
		}
		else 
		{
			front++;
		}
	}
	
}
int main()
{
	NODE*root;
	root=generateRandomBST(5,300);
	
	cout<<"the pre Order result is:"<<endl;
	preOrder(root);
	cout<<endl;
	cout<<"the in Order result is:"<<endl;
	inOrder(root);
	cout<<endl;
	cout<<"the post Order result is:"<<endl;
	postOrder(root);
	cout<<endl;
	cout<<"the level Order result is:"<<endl;
	levelOrder(root);
	cout<<endl;
	
	return 0;
	
	 
	 
	
}

运行: