java二叉樹遍歷,java二叉樹遍歷非遞歸

本文目錄一覽：

• 1、java實現二叉樹層次遍歷
• 2、java二叉樹的順序表實現
• 3、java一個關於二叉樹的簡單編程題
• 4、java中的遍歷是什麼意思？

java實現二叉樹層次遍歷

import java.util.ArrayList;

public class TreeNode {

private TreeNode leftNode;

private TreeNode rightNode;

private String nodeName;

public TreeNode getLeftNode() {

return leftNode;

}

public void setLeftNode(TreeNode leftNode) {

this.leftNode = leftNode;

}

public TreeNode getRightNode() {

return rightNode;

}

public void setRightNode(TreeNode rightNode) {

this.rightNode = rightNode;

}

public String getNodeName() {

return nodeName;

}

public void setNodeName(String nodeName) {

this.nodeName = nodeName;

}

public static int level=0;

public static void findNodeByLevel(ArrayListTreeNode nodes){

if(nodes==null||nodes.size()==0){

return ;

}

level++;

ArrayListTreeNode temp = new ArrayList();

for(TreeNode node:nodes){

System.out.println(“第”+level+”層:”+node.getNodeName());

if(node.getLeftNode()!=null){

temp.add(node.getLeftNode());

}

if(node.getRightNode()!=null){

temp.add(node.getRightNode());

}

}

nodes.removeAll(nodes);

findNodeByLevel(temp);

}

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

TreeNode root = new TreeNode();

root.setNodeName(“root”);

TreeNode node1 = new TreeNode();

node1.setNodeName(“node1”);

TreeNode node3 = new TreeNode();

node3.setNodeName(“node3”);

TreeNode node7 = new TreeNode();

node7.setNodeName(“node7”);

TreeNode node8 = new TreeNode();

node8.setNodeName(“node8”);

TreeNode node4 = new TreeNode();

node4.setNodeName(“node4”);

TreeNode node2 = new TreeNode();

node2.setNodeName(“node2”);

TreeNode node5 = new TreeNode();

node5.setNodeName(“node5”);

TreeNode node6 = new TreeNode();

node6.setNodeName(“node6”);

root.setLeftNode(node1);

node1.setLeftNode(node3);

node3.setLeftNode(node7);

node3.setRightNode(node8);

node1.setRightNode(node4);

root.setRightNode(node2);

node2.setLeftNode(node5);

node2.setRightNode(node6);

ArrayListTreeNode nodes = new ArrayListTreeNode();

nodes.add(root);

findNodeByLevel(nodes);

}

}

java二叉樹的順序表實現

做了很多年的程序員，覺得什麼樹的設計並不是非常實用。二叉樹有順序存儲，當一個insert大量同時順序自增插入的時候，樹就會失去平衡。樹的一方為了不讓塌陷，會增大樹的高度。性能會非常不好。以上是題外話。分析需求在寫代碼。

import java.util.List;

import java.util.LinkedList;

public class Bintrees {

private int[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9};

private static ListNode nodeList = null;

private static class Node {

Node leftChild;

Node rightChild;

int data;

Node(int newData) {

leftChild = null;

rightChild = null;

data = newData;

}

}

// 創建二叉樹

public void createBintree() {

nodeList = new LinkedListNode();

// 將數組的值轉換為node

for (int nodeIndex = 0; nodeIndex array.length; nodeIndex++) {

nodeList.add(new Node(array[nodeIndex]));

}

// 對除最後一個父節點按照父節點和孩子節點的數字關係建立二叉樹

for (int parentIndex = 0; parentIndex array.length / 2 – 1; parentIndex++) {

nodeList.get(parentIndex).leftChild = nodeList.get(parentIndex * 2 + 1);

nodeList.get(parentIndex).rightChild = nodeList.get(parentIndex * 2 + 2);

}

// 最後一個父節點

int lastParentIndex = array.length / 2 – 1;

// 左孩子

nodeList.get(lastParentIndex).leftChild = nodeList.get(lastParentIndex * 2 + 1);

// 如果為奇數，建立右孩子

if (array.length % 2 == 1) {

nodeList.get(lastParentIndex).rightChild = nodeList.get(lastParentIndex * 2 + 2);

}

}

// 前序遍歷

public static void preOrderTraverse(Node node) {

if (node == null) {

return;

}

System.out.print(node.data + ” “);

preOrderTraverse(node.leftChild);

preOrderTraverse(node.rightChild);

}

// 中序遍歷

public static void inOrderTraverse(Node node) {

if (node == null) {

return;

}

inOrderTraverse(node.leftChild);

System.out.print(node.data + ” “);

inOrderTraverse(node.rightChild);

}

// 後序遍歷

public static void postOrderTraverse(Node node) {

if (node == null) {

return;

}

postOrderTraverse(node.leftChild);

postOrderTraverse(node.rightChild);

System.out.print(node.data + ” “);

}

public static void main(String[] args) {

Bintrees binTree = new Bintrees();

binTree.createBintree();

Node root = nodeList.get(0);

System.out.println(“前序遍歷：”);

preOrderTraverse(root);

System.out.println();

System.out.println(“中序遍歷：”);

inOrderTraverse(root);

System.out.println();

System.out.println(“後序遍歷：”);

postOrderTraverse(root);

}

}

java一個關於二叉樹的簡單編程題

定義一個結點類：

public class Node {

private int value;

private Node leftNode;

private Node rightNode;

public Node getRightNode() {

return rightNode;

}

public void setRightNode(Node rightNode) {

this.rightNode = rightNode;

}

public int getValue() {

return value;

}

public void setValue(int value) {

this.value = value;

}

public Node getLeftNode() {

return leftNode;

}

public void setLeftNode(Node leftNode) {

this.leftNode = leftNode;

}

}

初始化結點樹：

public void initNodeTree()

{

int nodeNumber;

HashMapString, Integer map = new HashMapString, Integer();

Node nodeTree = new Node();

Scanner reader = new Scanner(System.in);

nodeNumber = reader.nextInt();

for(int i = 0; i nodeNumber; i++) {

int value = reader.nextInt();

String str = reader.next();

map.put(str, value);

}

if (map.containsKey(“#”)) {

int value = map.get(“#”);

nodeTree.setValue(value);

setChildNode(map, value, nodeTree);

}

preTraversal(nodeTree);

}

private void setChildNode(HashMapString, Integer map, int nodeValue, Node parentNode) {

int value = 0;

if (map.containsKey(“L” + nodeValue)) {

value = map.get(“L” + nodeValue);

Node leftNode = new Node();

leftNode.setValue(value);

parentNode.setLeftNode(leftNode);

setChildNode(map, value, leftNode);

}

if (map.containsKey(“R” + nodeValue)) {

value = map.get(“R” + nodeValue);

Node rightNode = new Node();

rightNode.setValue(value);

parentNode.setRightNode(rightNode);

setChildNode(map, value, rightNode);

}

}

前序遍歷該結點樹：

public void preTraversal(Node nodeTree) {

if (nodeTree != null) {

System.out.print(nodeTree.getValue() + “\t”);

preTraversal(nodeTree.getLeftNode());

preTraversal(nodeTree.getRightNode());

}

}

java中的遍歷是什麼意思？

遍歷就是把每個元素都訪問一次.比如一個二叉樹,遍歷二叉樹意思就是把二叉樹中的每個元素都訪問一次