先创建一个二叉树,并添加结点,然后根据结点id删除对应的结点。
一、代码
import java.util.Scanner;
public class BinaryTreeDemo {
public static void main(String[] args) {
BinaryTree binaryTree = new BinaryTree();
HeroNode root = new HeroNode(1, "宋江");
HeroNode node2 = new HeroNode(2, "吴用");
HeroNode node3 = new HeroNode(3, "卢俊义");
HeroNode node4 = new HeroNode(4, "林冲");
HeroNode node5 = new HeroNode(5, "关胜");
binaryTree.setRoot(root);
root.setLeft(node2);
root.setRight(node3);
node3.setRight(node4);
node3.setLeft(node5);
System.out.println("前序遍历");
binaryTree.preOrder();
System.out.println("中序遍历");
binaryTree.infixOrder();
System.out.println("后序遍历");
binaryTree.postOrder();
Scanner scanner = new Scanner(System.in);
int id;
System.out.println("删除前,前序遍历:");
binaryTree.preOrder();
System.out.println("输入你要删除的英雄编号:");
id = scanner.nextInt();
binaryTree.delNode(id);
System.out.println("删除后,前序遍历:");
binaryTree.preOrder();
}
}
class BinaryTree{
private HeroNode root;
public void setRoot(HeroNode root) {
this.root = root;
}
public void preOrder() {
if(this.root != null) {
this.root.preOrder();
}else {
System.out.println("二叉树为空,无法遍历");
}
}
public void infixOrder() {
if(this.root != null) {
this.root.infixOrder();
}else {
System.out.println("二叉树为空,无法遍历");
}
}
public void postOrder() {
if(root != null) {
this.root.postOrder();
}else {
System.out.println("二叉树为空,无法遍历");
}
}
public HeroNode preOrderSearch(int id) {
if(root != null) {
return root.preOrderSearch(id);
}else {
return null;
}
}
public HeroNode infixOrderSearch(int id) {
if(root != null) {
return root.infixOrderSearch(id);
}else {
return null;
}
}
public HeroNode postOrderSearch(int id) {
if(root != null) {
return root.postOrderSearch(id);
}else {
return null;
}
}
public void delNode(int id) {
if(root != null) {
if(root.getId() == id) {
root = null;
}else {
root.delNode(id);
}
}else {
System.out.println("空树");
}
}
}
class HeroNode{
private int id;
private String name;
private HeroNode left;
private HeroNode right;
public HeroNode(int id, String name) {
this.id = id;
this.name = name;
}
public void setId(int id) {
this.id = id;
}
public int getId() {
return id;
}
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
public void setLeft(HeroNode left) {
this.left = left;
}
public HeroNode getLeft() {
return left;
}
public void setRight(HeroNode right) {
this.right = right;
}
public HeroNode getRight() {
return right;
}
public String toString() {
return "[id = " + id + ", name = " + name + "]";
}
public void delNode(int id) {
if(this.left != null && this.left.id == id) {
this.left = null;
return;
}
if(this.right != null && this.right.id == id) {
this.right = null;
return;
}
if(this.left != null) {
this.left.delNode(id);
}
if(this.right != null) {
this.right.delNode(id);
}
}
public void preOrder() {
System.out.println(this);
if(this.left != null) {
this.left.preOrder();
}
if(this.right != null) {
this.right.preOrder();
}
}
public void infixOrder() {
if(this.left != null) {
this.left.infixOrder();
}
System.out.println(this);
if(this.right != null) {
this.right.infixOrder();
}
}
public void postOrder() {
if(this.left != null) {
this.left.postOrder();
}
if(this.right != null) {
this.right.postOrder();
}
System.out.println(this);
}
public HeroNode preOrderSearch(int id) {
System.out.println("进入前序遍历查找一次");
if(this.id == id) {
return this;
}
HeroNode resNode = null;
if(this.left != null) {
resNode = this.left.preOrderSearch(id);
}
if(resNode != null) {
return resNode;
}
if(this.right != null) {
resNode = this.right.preOrderSearch(id);
}
return resNode;
}
public HeroNode infixOrderSearch(int id) {
HeroNode resNode = null;
if(this.left != null) {
resNode = this.left.infixOrderSearch(id);
}
if(resNode != null) {
return resNode;
}
System.out.println("进入中序遍历查找一次");
if(this.id == id) {
return this;
}
if(this.right != null) {
resNode = this.right.infixOrderSearch(id);
}
return resNode;
}
public HeroNode postOrderSearch(int id) {
HeroNode resNode = null;
if(this.left != null) {
resNode = this.left.postOrderSearch(id);
}
if(resNode != null) {
return resNode;
}
if(this.right != null) {
resNode = this.right.postOrderSearch(id);
}
if(resNode != null) {
return resNode;
}
System.out.println("进入后序遍历查找一次");
if(this.id == id) {
return this;
}
return resNode;
}
}
二、结果
1. 删除编号为5的结点
前序遍历
[id = 1, name = 宋江]
[id = 2, name = 吴用]
[id = 3, name = 卢俊义]
[id = 5, name = 关胜]
[id = 4, name = 林冲]
中序遍历
[id = 2, name = 吴用]
[id = 1, name = 宋江]
[id = 5, name = 关胜]
[id = 3, name = 卢俊义]
[id = 4, name = 林冲]
后序遍历
[id = 2, name = 吴用]
[id = 5, name = 关胜]
[id = 4, name = 林冲]
[id = 3, name = 卢俊义]
[id = 1, name = 宋江]
删除前,前序遍历:
[id = 1, name = 宋江]
[id = 2, name = 吴用]
[id = 3, name = 卢俊义]
[id = 5, name = 关胜]
[id = 4, name = 林冲]
输入你要删除的英雄编号:
5
删除后,前序遍历:
[id = 1, name = 宋江]
[id = 2, name = 吴用]
[id = 3, name = 卢俊义]
[id = 4, name = 林冲]
2. 删除编号为3的结点
前序遍历
[id = 1, name = 宋江]
[id = 2, name = 吴用]
[id = 3, name = 卢俊义]
[id = 5, name = 关胜]
[id = 4, name = 林冲]
中序遍历
[id = 2, name = 吴用]
[id = 1, name = 宋江]
[id = 5, name = 关胜]
[id = 3, name = 卢俊义]
[id = 4, name = 林冲]
后序遍历
[id = 2, name = 吴用]
[id = 5, name = 关胜]
[id = 4, name = 林冲]
[id = 3, name = 卢俊义]
[id = 1, name = 宋江]
删除前,前序遍历:
[id = 1, name = 宋江]
[id = 2, name = 吴用]
[id = 3, name = 卢俊义]
[id = 5, name = 关胜]
[id = 4, name = 林冲]
输入你要删除的英雄编号:
3
删除后,前序遍历:
[id = 1, name = 宋江]
[id = 2, name = 吴用]
3. 删除编号为1的结点
前序遍历
[id = 1, name = 宋江]
[id = 2, name = 吴用]
[id = 3, name = 卢俊义]
[id = 5, name = 关胜]
[id = 4, name = 林冲]
中序遍历
[id = 2, name = 吴用]
[id = 1, name = 宋江]
[id = 5, name = 关胜]
[id = 3, name = 卢俊义]
[id = 4, name = 林冲]
后序遍历
[id = 2, name = 吴用]
[id = 5, name = 关胜]
[id = 4, name = 林冲]
[id = 3, name = 卢俊义]
[id = 1, name = 宋江]
删除前,前序遍历:
[id = 1, name = 宋江]
[id = 2, name = 吴用]
[id = 3, name = 卢俊义]
[id = 5, name = 关胜]
[id = 4, name = 林冲]
输入你要删除的英雄编号:
1
删除后,前序遍历:
二叉树为空,无法遍历