先序遍历：中、左、右

中序遍历：左、中、右

后序遍历：左、右、中

 

比如下面这科树

             1

        2       3

 

    4    5   6    7

 

 

 package com.sangfor.tree;  public class Node {  public int value;  public Node left;  public Node right;  public Node(int value) {  this.value = value;  }  
} 

package com.sangfor.tree;import java.util.Stack;public class ForEachTree {public static void main(String[] args) {Node node1 = new Node(1);Node node2 = new Node(2);Node node3 = new Node(3);Node node4 = new Node(4);Node node5 = new Node(5);Node node6 = new Node(6);Node node7 = new Node(7);node1.left = node2;node1.right = node3;node2.left = node4;node2.right =