给定一个二叉树,返回所有从根节点到叶子节点的路径。
说明: 叶子节点是指没有子节点的节点。
示例:
输入: 1 / \ 2 3 \ 5 输出: ["1->2->5", "1->3"] 解释: 所有根节点到叶子节点的路径为: 1->2->5, 1->3
#!/usr/bin/python3
# -*- coding: utf-8 -*-
# @Time: 2018/8/14
# @Author: xfLi
#@解题思路:字符串添加路径节点,再将字符串添加到列表中
class TreeNode(object):
def __init__(self,val=None, left=None, right=None):
self.val = val
self.left = left
self.right = right
def binaryTreePaths(root):
"""
:type root: TreeNode
:rtype: List[str]
"""
res = []
path = ''
if root is None:
return []
subTreePath(root, path, res)
return res
def subTreePath(root, path, res):
path += str(root.val)
if root.left is None and root.right is None:
res.append(path)
if root.left is not None:
subTreePath(root.left, path + '->', res)
if root.right is not None:
subTreePath(root.right, path + '->', res)
if __name__ == '__main__':
root = TreeNode(val=1, left=TreeNode(2, left=TreeNode(3), right=TreeNode(4)),
right=TreeNode(5, left=TreeNode(6), right=TreeNode(7)))
result = binaryTreePaths(root)
print(result)