class TreeNode:
def init(self, x):
self.val = x
self.left = None
self.right = None
代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
@param root TreeNode类 the root of binary tree
@return int整型二维数组
class Solution: def threeOrders(self , root: TreeNode) -> List[List[int]]: # write code here pre_values = [] in_values = [] post_values =[] # 先序遍历 def pre_order(node): if node is None: return None
pre_values.append(node.val)
pre_order(node.left)
pre_order(node.right)
return pre_values
# 中序遍历
def in_order(node):
if node is None:
return None
in_order(node.left)
in_values.append(node.val)
in_order(node.right)
return in_values
# 后序遍历
def post_order(node):
if node is None:
return None
post_order(node.left)
post_order(node.right)
post_values.append(node.val)
return post_values
res = []
res.append(pre_order(root))
res.append(in_order(root))
res.append(post_order(root))
return res