<LeetCode><Easy>257BinaryTreePaths （深度优先搜索）（列表深拷贝）

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"]

#Python2  48ms

# 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]
"""
paths=[]
if root is None:
return paths
def add(root,tList):    #Note that memory copy
tList.append(root.val)
status=1
if root.left:
lList=tList[:]    #deep copy
add(root.left,lList)
status=0
if root.right:
rList=tList[:]
add(root.right,rList)
status=0
if status:
paths.append("->".join([str(t) for t in tList]))
add(root,[])
return paths