sys.path.append("..")
from typing import Optional
from utils import TreeNode
class Solution:
def diameterOfBinaryTree(self, root: Optional[TreeNode]) -> int:
paths = [0]
def helper(node):
if not (node.left or node.right):
return 0
lh = helper(node.left) + 1 if node.left else 0
rh = helper(node.right) + 1 if node.right else 0
paths[0] = max(paths[0], lh + rh)
return max(lh, rh)
helper(root)
return paths[0]
if __name__ == '__main__':
s = Solution()
print(s.diameterOfBinaryTree(TreeNode.from_list([1, 2, 3, 4, 5])))
from typing import List, Optional
from utils import TreeNode
class Solution:
def rightSideView(self, root: Optional[TreeNode]) -> List[int]:
if not root:
return []
queue = [(0, root)]
nodes = {}
while queue:
level, node = queue.pop()
nodes[level] = node.val
if node.left:
queue.insert(0, (level + 1, node.left))
if node.right:
queue.insert(0, (level + 1, node.right))
return list(nodes.values())
if __name__ == '__main__':
s = Solution()
root = TreeNode.from_list([1, 2, 3, None, 5, None, 4])
print(s.rightSideView(root))
class Solution:
def deleteNode(self, root: Optional[TreeNode],
key: int) -> Optional[TreeNode]:
if not root:
return None
if key < root.val:
root.left = self.deleteNode(root.left, key)
elif key > root.val:
root.right = self.deleteNode(root.right, key)
else:
if not root.left:
return root.right
if not root.right:
return root.left
rightSmallest = root.right
while rightSmallest.left:
rightSmallest = rightSmallest.left
rightSmallest.left = root.left
return root.right
return root
if __name__ == '__main__':
s = Solution()
root = TreeNode.from_list([5, 3, 6, 2, 4, None, 7])
ans = s.deleteNode(root, 3)
print(ans.to_list())
