return
stack = []
res, first, second = None, None, None
node = root
while True:
while node:
stack.append(node)
node = node.left
if not stack:
break
tmp_node = stack.pop()
if res and res.val > tmp_node.val:
if not first:
first = tmp_node
second = res
res = tmp_node
node = tmp_node.right
first.val, second.val = second.val, first.val
return root
if __name__ == '__main__':
preOrder = [3, 1, 4, 2]
inOrder = [1, 3, 2, 4]
root = reConstructBinaryTree(preOrder, inOrder)
s = Solution()
p = PrintTree()
root = s.recoverTree1(root)
p. in_order(root)
print(p.res)
# -*- coding: utf-8 -*-
# @Author : Jing
# @FileName: 100. Same Tree.py
# @IDE: PyCharm
# https://leetcode.com/problems/same-tree/
from base import TreeNode, reConstructBinaryTree, PrintTree
class Solution:
def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
if not p and not q:
return True
if not p or not q:
return False
if p.val != q.val:
return False
return self.isSameTree(p.left, q.left) and self.isSameTree(
p.right, q.right)
if __name__ == '__main__':
pre_order = [1, 2, 3]
in_order = [2, 1, 3]
root = reConstructBinaryTree(pre_order, in_order)
p = PrintTree()
p.pre_order(root)
p.print_tree()
s = Solution()
print(s.isSameTree(root, root))
q: 'TreeNode'):
self.helper(root, p, q)
return self.res
def lowestCommonAncestor4(self, root: 'TreeNode', p: 'TreeNode',
q: 'TreeNode'):
stack, tmp_set, parents = [root], set(), {root: None}
while p not in parents or q not in parents:
root = stack.pop()
if root.left:
parents[root.left] = root
stack.append(root.left)
if root.right:
parents[root.right] = root
stack.append(root.right)
while q:
tmp_set.add(q)
q = parents[q]
while p not in tmp_set:
p = parents[p]
return p
if __name__ == '__main__':
pre_order = [6, 2, 0, 4, 3, 5, 8, 7, 9]
in_order = [0, 2, 3, 4, 5, 6, 7, 8, 9]
root = reConstructBinaryTree(pre_order, in_order)
P = PrintTree()
P.pre_order(root)
P.print_tree()