Java递归方法遍历二叉树的代码

Posted 2021-02-08 不是叫兽

将内容过程中经常用的内容做个记录，如下内容内容是关于Java递归方法遍历二叉树的内容。

package com.wzs;

public class TestBinaryTree {
public static void main(String[] args) {
Node<String> g = new Node<String>("G", null, null);
Node<String> e = new Node<String>("E", null, null);
Node<String> f = new Node<String>("F", null, null);
Node<String> d = new Node<String>("D", null, g);
Node<String> b = new Node<String>("B", d, e);
Node<String> c = new Node<String>("C", null, f);
Node<String> a = new Node<String>("A", b, c);

System.out.println("生成的二叉树:");
System.out.println(" A");
System.out.println(" | ");
System.out.println(" |---------|");
System.out.println(" B C");
System.out.println(" | |");
System.out.println(" |---------| -----|");
System.out.println(" D E F");
System.out.println(" |");
System.out.println(" ----|");
System.out.println(" G");

System.out.println("二叉树深度：" + BinaryTree.getDepth(a));

System.out.print("前序遍历：");
BinaryTree.priorderTraversal(a);
System.out.println();

System.out.print("中序遍历：");
BinaryTree.inorderTraversal(a);
System.out.println();

System.out.print("后序遍历：");
BinaryTree.postorderTraversal(a);
System.out.println();
}
}

class BinaryTree {
static <T> void priorderTraversal(Node<T> node) {
if (node != null) {
visitNode(node);
priorderTraversal(node.getLeftChild());
priorderTraversal(node.getRightChild());
}
}

static <T> void inorderTraversal(Node<T> node) {
if (node != null) {
inorderTraversal(node.getLeftChild());
visitNode(node);
inorderTraversal(node.getRightChild());
}
}

static <T> void postorderTraversal(Node<T> node) {
if (node != null) {
postorderTraversal(node.getLeftChild());
postorderTraversal(node.getRightChild());
visitNode(node);
}
}

static <T> int getDepth(Node<T> node) {
if (node == null) {
return 0;
}
int leftDepth = 0;
int rightDepth = 0;
leftDepth = getDepth(node.getLeftChild());
rightDepth = getDepth(node.getRightChild());
return (leftDepth > rightDepth ? leftDepth : rightDepth) + 1;
}

static <T> void visitNode(Node<T> node) {
System.out.print(node.getKey() + " ");
}
}

class Node<T> {
private T key;
private Node<T> leftChild;
private Node<T> rightChild;

public Node() {

}

public Node(T key, Node<T> leftChild, Node<T> rightChild) {
super();
this.key = key;
this.leftChild = leftChild;
this.rightChild = rightChild;
}

public T getKey() {
return key;
}

public void setKey(T key) {
this.key = key;
}

public Node<T> getLeftChild() {
return leftChild;
}

public void setLeftChild(Node<T> leftChild) {
this.leftChild = leftChild;
}

public Node<T> getRightChild() {
return rightChild;
}

public void setRightChild(Node<T> rightChild) {
this.rightChild = rightChild;
}

}

输出结果生成的二叉树:A||---------|BC|||---------|-----|DEF|----|G二叉树深度：4前序遍历：ABDGECF中序遍历：DGBEACF后序遍历：GDEBFCA