给定一棵二叉树，返回该树的所有的路径。
class Node(object):
def __init__(self, value):
self.value = value
self.left_node =None
self.right_node =None
def find_path(root, pathes):
"""
返回所有的路径
:param root: 当前节点
:param pathes: 当前节点包含的路径
:return:
"""
if not root:
return pathes
else:
pathes =set(path +str(root.value)for pathin pathes)
left_pathes = find_path(root.left_node, pathes)
right_pathes = find_path(root.right_node, pathes)
all_pathes = left_pathes | right_pathes
return all_pathes
