637. Average of Levels in Binary Tree

637. Average of Levels in Binary Tree

 

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def averageOfLevels(self, root: Optional[TreeNode]) -> List[float]:
    	"""
        # BFS..로..큐로 풀자
        """
        res = []
        que = deque([root])

        while(que):
            l = len(que)

            sum = 0
            for i in range(l):
                node = que.popleft()
                sum += node.val

                if node.left:
                    que.append(node.left)
                if node.right:
                    que.append(node.right)
            res.append(sum/l)

        return res