Java实现的二叉树常用操作【前序建树，前中后递归非递归遍历及层序遍历】

这篇文章主要介绍了Java实现的二叉树常用操作,包括二叉树的前序建树，前中后递归非递归遍历及层序遍历等相关操作技巧,需要的朋友可以参考下

本文实例讲述了Java实现的二叉树常用操作。分享给大家供大家参考，具体如下：

import java.util.arraydeque; import java.util.Queue; import java.util.Stack; //二叉树的建树，前中后 递归非递归遍历 层序遍历 //Node节点 class Node { int element; Node left; Node right; public Node() { } public Node(int element) { this.element = element; } } // BinaryTree public class Tree { // creat tree from array public static Node creatTree(int[] data, int i) { if (i >= data.length || data[i] == -1) return null; Node temp = new Node(data[i]); temp.left = creatTree(data, i * 2 + 1); temp.right = creatTree(data, i * 2 + 2); return temp; } // pre前序遍历递归 public static void pre(Node temp) { if (temp == null) return; System.out.print(temp.element + " "); pre(temp.left); pre(temp.right); } // mid中序遍历递归 public static void mid(Node temp) { if (temp == null) return; mid(temp.left); System.out.print(temp.element + " "); mid(temp.right); } // last后序遍历递归 public static void last(Node temp) { if (temp == null) return; last(temp.left); last(temp.right); System.out.print(temp.element + " "); } // pre1前序遍历非递归 public static void pre1(Node temp) { Stack stack = new Stack(); while (temp != null || !stack.isEmpty()) { while (temp != null) { stack.push(temp); System.out.print(temp.element + " "); temp = temp.left; } if (!stack.isEmpty()) { temp = stack.pop().right; } } } // mid1中序遍历非递归 public static void mid1(Node temp) { Stack stack = new Stack(); while (temp != null || !stack.isEmpty()) { while (temp != null) { stack.push(temp); temp = temp.left; } if (!stack.isEmpty()) { temp = stack.pop(); System.out.print(temp.element + " "); temp = temp.right; } } } // last1后序遍历非递归 public static void last1(Node temp) { Stack stack = new Stack(); Stack stack2 = new Stack(); while (temp != null || !stack.isEmpty()) { while (temp != null) { stack.push(temp); stack2.push(temp); temp = temp.right; } if (!stack.isEmpty()) { temp = stack.pop().left; } } while (!stack2.isEmpty()) System.out.print(stack2.pop().element + " "); } // ceng层序遍历 public static void ceng(Node temp) { if (temp == null) return; Queue queue = new arraydeque(); queue.offer(temp); while (!queue.isEmpty()) { temp = queue.poll(); System.out.print(temp.element + " "); if (temp.left != null) queue.offer(temp.left); if (temp.right != null) queue.offer(temp.right); } } // Demo public static void main(String[] args) { int[] array = { 1, 2, 3, 4, 5, 6, 7, -1, -1, 10, -1, -1, 13 }; Node tree = creatTree(array, 0); System.out.println("编程之家测试结果："); pre(tree); System.out.println(); pre1(tree); System.out.println(); mid(tree); System.out.println(); mid1(tree); System.out.println(); last(tree); System.out.println(); last1(tree); System.out.println(); ceng(tree); } }

运行结果：

更多关于java算法相关内容感兴趣的读者可查看本站专题：《Java数据结构与算法教程》、《Java操作DOM节点技巧总结》、《Java文件与目录操作技巧汇总》和《Java缓存操作技巧汇总》

希望本文所述对大家java程序设计有所帮助。