Solution.py

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None


class Solution:
    def listOfDepth(self, tree: TreeNode) -> List[ListNode]:
        ans = []
        q = deque([tree])
        while q:
            dummy = cur = ListNode(0)
            for _ in range(len(q)):
                node = q.popleft()
                cur.next = ListNode(node.val)
                cur = cur.next
                if node.left:
                    q.append(node.left)
                if node.right:
                    q.append(node.right)
            ans.append(dummy.next)
        return ans