Given the root of a binary tree, return the average value of the nodes on each level in the form of an array. Answers within 10-5 of the actual answer will be accepted.
Example 1:
Input: root = [3,9,20,null,null,15,7] Output: [3.00000,14.50000,11.00000] Explanation: The average value of nodes on level 0 is 3, on level 1 is 14.5, and on level 2 is 11. Hence return [3, 14.5, 11].
- code
class Solution:
def averageOfLevels(self, root: Optional[TreeNode]) -> List[float]:
res = []
level = [root]
while level:
res.append(sum(node.val for node in level if node)/len(level))
level = [i for node in level for i in (node.left, node.right) if i]
return res