For example, given the following binary tree:
1
/ \
2 3
\
5
All root-to-leaf paths are:
["1->2->5", "1->3"]
给定一个二叉树,输出从根到叶子节点的路径。用递归来完成,代码如下:
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public List<String> binaryTreePaths(TreeNode root) { List<String> list = new ArrayList<String>(); if(root == null) return list; getPath(root, String.valueOf(root.val), list); return list; } public void getPath(TreeNode root, String s, List<String> list) { if(root.left == null && root.right == null) list.add(s); if(root.left != null) getPath(root.left, s + "->" + root.left.val, list); if(root.right != null) getPath(root.right, s + "->" + root.right.val, list); } }