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"]
思路:递归,将当前节点的数字加在此节点的左子树和右子树上
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
def binaryTreePaths(self, root: TreeNode) -> List[str]:
result = list()
if root == None:
return result
if root.left == None and root.right == None:
result.append(str(root.val))
return result
leftStr = self.binaryTreePaths(root.left)
for s in leftStr:
result.append(str(root.val) + '->' + str(s))
rightStr = self.binaryTreePaths(root.right)
for s in rightStr:
result.append(str(root.val) + '->' + str(s))
return result