import sys
sys.path.append('com/DataStructure/Python')
from BinarySearchTree import BinarySearchTree
class Solution:
def isValidTree(self, root, minN, maxN):
if root is None:
return True
if root.val > minN and root.val < maxN:
return self.isValidTree(root.left, minN,
root.val) and self.isValidTree(
root.right, root.val, maxN)
else:
return False
def isValidBST(self, root):
return self.isValidTree(root, float('-inf'), float('inf'))
test = BinarySearchTree()
test.addNode(6)
test.addNode(4)
test.addNode(8)
test.printTree(test.getRoot())
sol = Solution()
print(sol.isValidBST(test.getRoot()))
def invertTreeDfs(self, root):
stack = [root]
while stack:
current = stack.pop()
if current:
current.left, current.right = current.right, current.left
stack.append(current.left)
stack.append(current.right)
return root
def invertTreeRecursion(self, root):
if not root:
return
root.left, root.right = root.right, root.left
self.invertTreeRecursion(root.left)
self.invertTreeRecursion(root.right)
return root
test = BinarySearchTree()
test.addNode(4)
test.addNode(2)
test.addNode(7)
test.addNode(1)
test.addNode(3)
test.addNode(6)
test.addNode(9)
test.printTreeBfs(test.getRoot())
sol = Solution()
test.printTreeBfs(sol.invertTreeRecursion(test.getRoot()))
