def _dfs_invert(node: TreeNode):
if node.left and node.right:
node.left, node.right = node.right, node.left
elif node.left and not node.right:
node.right, node.left = node.left, None
elif node.right and not node.left:
node.left, node.right = node.right, None
if node.left:
_dfs_invert(node.left)
if node.right:
_dfs_invert(node.right)
# @Date : 2019/5/21 14:59
# @Author: hlliu
from queue import LifoQueue
from models.binary_tree import TreeNode
class Solution:
def preorderTraversal(self, root: TreeNode):
res = []
stack = LifoQueue()
cur = root
while cur is not None or not stack.empty():
if cur is not None:
stack.put(cur)
res.append(cur.val)
cur = cur.left
else:
cur = stack.get().right
return res
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)
root.left.right = TreeNode(5)
s = Solution()
print(s.preorderTraversal(root))
from pathlib import Path
import sys
sys.path.append(str(Path(__file__).parent.parent.absolute()))
from models.binary_tree import TreeNode, arr_to_node
class Solution:
def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
while p != None or q != None:
if p == None or q == None or (p.val != q.val):
return False
else:
if not self.isSameTree(p.left, q.left):
return False
if not self.isSameTree(p.right, q.right):
return False
return True
return True
s = Solution()
p = TreeNode(1)
p.left = TreeNode(2)
p.right = TreeNode(3)
q = TreeNode(1)
q.left = TreeNode(2)
result = s.isSameTree(p, q)
print(result)