import collections
from typing import List
from Python.q0tree import TreeNode, stringToTreeNode
class Solution:
def levelOrder(self, root: TreeNode) -> List[List[int]]:
if not root:
return []
result = collections.defaultdict(list)
queue = collections.deque([(root, 0)])
while queue:
tree_node, level = queue.popleft()
if not tree_node:
continue
result[level].append(tree_node.val)
queue.append((tree_node.left, level + 1))
queue.append((tree_node.right, level + 1))
return list(result.values())
s = Solution()
root = stringToTreeNode('[3,9,20,null,null,15,7]')
print(s.levelOrder(root))
exit(0)
import collections
from typing import List
from Python.q0tree import TreeNode, stringToTreeNode
class Solution:
def rightSideView(self, root: TreeNode) -> List[int]:
if not root:
return []
res = []
queue = collections.deque([root])
while queue:
level_length = len(queue)
for i in range(level_length):
tree_node = queue.popleft()
if i == (level_length - 1):
res.append(tree_node.val)
if tree_node.left:
queue.append(tree_node.left)
if tree_node.right:
queue.append(tree_node.right)
return res
s = Solution()
root = stringToTreeNode('[1,2,3,null,5,null,4]')
print(s.rightSideView(root))
exit(0)
import collections
from Python.q0tree import TreeNode, stringToTreeNode
class Solution:
def minDepth(self, root: TreeNode) -> int:
if not root:
return 0
queue = collections.deque([(root, 1)])
while (queue):
node, level = queue.popleft()
if not node:
continue
if not node.left and not node.right:
return level
queue.append((node.left, level + 1))
queue.append((node.right, level + 1))
s = Solution()
# root = stringToTreeNode('[3,9,20,null,null,15,7]')
root = stringToTreeNode('[2,null,3,null,4,null,5,null,6]')
root = stringToTreeNode('[3,9,20,null,null,15,7]')
print(s.minDepth(root))
exit(0)
import collections
from Python.q0tree import stringToTreeNode
class Solution:
def connect(self, root: 'Node') -> 'Node':
if not root:
return root
queue = collections.deque([root])
while queue:
level_length = len(queue)
for i in range(level_length):
tree_node = queue.popleft()
if i == (level_length - 1):
tree_node.next = None
else:
tree_node.next = queue[0]
if tree_node.left:
queue.append(tree_node.left)
if tree_node.right:
queue.append(tree_node.right)
return root
s = Solution()
root = stringToTreeNode('[1,2,3,4,5,6,7]')
print(s.connect(root))
exit(0)