PAT04-树7 二叉搜索树的操作集（Java实现）

本题为浙大数据结构课后题：

BinTree Insert( BinTree BST, ElementType X ); 
BinTree Delete( BinTree BST, ElementType X ); 
Position Find( BinTree BST, ElementType X ); 
Position FindMin( BinTree BST ); 
Position FindMax( BinTree BST );

其中BinTree结构定义如下：

typedef struct TNode *Position; 
typedef Position BinTree; 
struct TNode{ 
ElementType Data; 
BinTree Left; 
BinTree Right; 
};

测试结果：105 8 6 2 4 1 0 10 9 7先序遍历：5 2 1 0 4 8 6 7 10 9 中序遍历：0 1 2 4 5 6 7 8 9 10 二叉树最小值=0二叉树最大值=10删除7,3,83不存在删除7,3,8之后的中序遍历：0 1 2 4 5 6 9 10 

下面是java实现的具体代码：

import java.util.Scanner;/* *建立二叉搜索树类  */class BinSearchNode{int value;BinSearchNode left;BinSearchNode right;BinSearchNode(int value){this.value=value;left=null;right=null;}}public class BinarySearchOperate {public static void main(String[] args) {// TODO Auto-generated method stubScanner sc=new Scanner(System.in);BinSearchNode head=null;int N=sc.nextInt();for(int i=0;i<N;i++){head=insert(sc.nextInt(),head);}System.out.println("先序遍历：");preOrder(head);System.out.println();System.out.println("中序遍历：");inOrder(head);System.out.println();System.out.println("二叉树最小值="+findMin(head));System.out.println("二叉树最大值="+findMax(head));System.out.println("删除7,3,8");head=delete(7,head);head=delete(3,head);head=delete(8,head);System.out.println("删除7,3,8之后的中序遍历：");inOrder(head);sc.close();}/* * 插入操作：这里默认插入元素不重复 */public static BinSearchNode insert(int x,BinSearchNode head){if(head==null){return new BinSearchNode(x);}if(x>head.value){head.right=insert(x,head.right);}else{head.left=insert(x,head.left);}return head;}/* * 递归实现前序遍历 */public static void preOrder(BinSearchNode head){System.out.print(head.value+" ");if(head.left!=null)preOrder(head.left);if(head.right!=null)preOrder(head.right);}/* * 递归实现中序遍历 */public static void inOrder(BinSearchNode head){if(head.left!=null)inOrder(head.left);System.out.print(head.value+" ");if(head.right!=null)inOrder(head.right);}/* * 找最小元：递归实现 */public static int findMin(BinSearchNode head){if(head.left!=null)return findMin(head.left);return head.value;}/* * 找最大元：非递归实现 */public static int findMax(BinSearchNode head){while(head.right!=null){head=head.right;}return head.value;}/* * 删除操作 */public static BinSearchNode delete(int x,BinSearchNode head){if(head==null){System.out.println(x+"不存在");return head;}if(x<head.value)head.left=delete(x,head.left);else if(x>head.value)head.right=delete(x,head.right);else if(head.left!=null && head.right!=null){head.value=findMin(head.right);head.right=delete(head.value,head.right);}elsehead=(head.left==null)?head.right:head.left;return head;}/* * 寻找节点操作 */public static boolean contains(int x,BinSearchNode head){if(head==null)return false;if(x>head.value)return contains(x,head.right);else if(x<head.value)return contains(x,head.left);elsereturn true;}}