java写二叉排序树的插入、查找和遍历

import java.util.*;


class Node
{
int key;
Node left;
Node right;
Node(int key)
{
this.key = key;
left = null;
right = null;
}
}


class Tree
{  
void insert(Node root,int k)
{
int value = root.key;
Node node = new Node(k);
if(k < value)
{
if(root.left == null)
{
root.left = node;
}
   else
   {
       insert(root.left,k);
}
}
else if(k > value)
{
   if(root.right == null)
{
       root.right = node;
}
else
{
insert(root.right,k);
}
}
}
void mid(Node root)
{
if(root == null)
return;
else
{
mid(root.left);
System.out.print(root.key + " ");
mid(root.right);
}
}
void level(Node root)
{
if(root == null)
return;
List<Node> queue = new LinkedList<Node>();
queue.add(root);
while(!(queue.isEmpty()))
{
Node temp = queue.remove(0);
System.out.print(temp.key + " ");
if(temp.left != null)
queue.add(temp.left);
if(temp.right != null)
queue.add(temp.right);
}
System.out.println();
}
void find(Node root,int k)
{
int value = root.key;
if(value == k)
{
System.out.println("Yes!");
}
else if(value != k)
{
if(value > k)
{
if(root.left != null)
   find(root.left,k);
else 
System.out.println("No!");
}
else if(value < k)
{
if(root.right != null)
   find(root.right,k);
else 
System.out.println("No!");
}
}
}
}


public class Test
{
public static void main(String args[])
{
@SuppressWarnings("resource")
Scanner scan = new Scanner(System.in);                                    //注意：这里使用了scanner类，用来从键盘输入
int n = scan.nextInt();
int array[] = new int[n];
for(int j = 0; j < n; j++)
array[j] = scan.nextInt();
Node root = new Node(array[0]);
Tree tree = new Tree();
for(int i = 0; i < array.length; i++)
{
tree.insert(root, array[i]);
}
tree.mid(root);
System.out.println();
tree.level(root);
System.out.print("请输入要查询的数字：");
int k = scan.nextInt();
tree.find(root, k);
}
}