樹的深度優先遍歷需要用到額外的資料結構--->棧；而廣度優先遍歷需要佇列來輔助；這裡以二叉樹為例來實現

import java.util.ArrayDeque;publicclassBinaryTree{staticclassTreeNode{int value;TreeNode left;TreeNode right;publicTreeNode(int value){this.value=value;}}TreeNode root;publicBinaryTree(int[] array){
        root=makeBinaryTreeByArray(array,1);
 
}/**
     * 採用遞迴的方式建立一顆二叉樹
     * 傳入的是二叉樹的陣列表示法
     * 構造後是二叉樹的二叉連結串列表示法
     */publicstaticTreeNode makeBinaryTreeByArray(int[] array,int index){if(index<array.length){int value=array[index];if(value!=0){TreeNode t=newTreeNode(value);
                array[index]=0;
                t.left=makeBinaryTreeByArray
 
(array,index*2);
                t.right=makeBinaryTreeByArray(array,index*2+1);return t;}}returnnull;}/**
     * 深度優先遍歷，相當於先根遍歷
     * 採用非遞迴實現
     * 需要輔助資料結構：棧
     */publicvoid depthOrderTraversal(){if(root==null){System.out.println("empty tree");return;}ArrayDeque<TreeNode> stack=newArrayDeque
 
<TreeNode>();
        stack.push(root);while(stack.isEmpty()==false){TreeNode node=stack.pop();System.out.print(node.value+"    ");if(node.right!=null){
                stack.push(node.right);}if(node.left!=null){
                stack.push(node.left);}}System.out.print("\n");}/**
     * 廣度優先遍歷
     * 採用非遞迴實現
     * 需要輔助資料結構：佇列
     */publicvoid levelOrderTraversal(){if(root==null){System.out.println("empty tree");return;}ArrayDeque<TreeNode> queue=newArrayDeque<TreeNode>();
        queue.add(root);while(queue.isEmpty()==false){TreeNode node=queue.remove();System.out.print(node.value+"    ");if(node.left!=null){
                queue.add(node.left);}if(node.right!=null){
                queue.add(node.right);}}System.out.print("\n");}/** 
     *                  13
     *                 /  \
     *               65    5
     *              /  \    \
     *             97  25   37
     *            /    /\   /
     *           22   4 28 32
     */publicstaticvoid main(String[] args){int[] arr={0,13,65,5,97,25,0,37,22,0,4,28,0,0,32,0};BinaryTree tree=newBinaryTree(arr);
        tree.depthOrderTraversal();
        tree.levelOrderTraversal();}}

http://outofmemory.cn/code-snippet/4189/biinary-tree-java