""" Given a binary tree, return all root-to-leaf paths. For example, given the following binary tree: 1 / \ 2 3 \ 5 All root-to-leaf paths are: ["1->2->5", "1->3"] """ # Definition for a binary tree node. # class TreeNode(object): # def __init__(self, x): # self.val = x # self.left = None # self.right = None class Solution(object): def binaryTreePaths(self, root): """ :type root: TreeNode :rtype: List[str] """ res = [] cand = [] self.binary_tree_paths(root, cand, res) return res def binary_tree_paths(self, root, cand, res): if root is None: return else: cand.append(root.val) if root.left is None and root.right is None: p = '->'.join(map(str, cand)) res.append(p) self.binary_tree_paths(root.left, cand, res) self.binary_tree_paths(root.right, cand, res) cand.pop()