[leetcode-二叉树后序遍历]--145. Binary Tree Postorder Traversal

Question 145. Binary Tree Postorder Traversal

Given a binary tree, return the postorder traversal of its nodes’ values.

For example:
Given binary tree {1,#,2,3},
1
\
2
/
3
return [3,2,1].

二叉树后序遍历

直接给出代码了：

/** * @param root * @return */public static List<Integer> postorderTraversal(TreeNode root) {    List<Integer> post = new ArrayList<Integer>();    postHelper(root, post);    return post;}private static void postHelper(TreeNode root, List<Integer> post) {    if(root==null) return;    postHelper(root.left, post);    postHelper(root.right, post);    post.add(root.val);}

完整代码github地址：
https://github.com/leetcode-hust/leetcode/blob/master/louyuting/src/leetcode/Question145.java