LC-0637 Easy LeetCode

637. Average of Levels in Binary Tree

Tree Depth-First Search Breadth-First Search Binary Tree

Read the full problem statement on LeetCode.

Difficulty: easy Acceptance: 74% Topics: Tree, Depth-First Search, Breadth-First Search, Binary Tree

Reading material

Reference solution (spoiler · python)

# Time:  O(n)
# Space: O(h)


class Solution(object):
    def averageOfLevels(self, root):
        """
        :type root: TreeNode
        :rtype: List[float]
        """
        result = []
        q = [root]
        while q:
            total, count = 0, 0
            next_q = []
            for n in q:
                total += n.val
                count += 1
                if n.left:
                    next_q.append(n.left)
                if n.right:
                    next_q.append(n.right)
            q = next_q
            result.append(float(total) / count)
        return result

Solution from kamyu104/LeetCode-Solutions · MIT