Watch 10 video solutions for Check Completeness of a Binary Tree, a medium level problem involving Tree, Breadth-First Search, Binary Tree. This walkthrough by Inside code has 224,587 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Given the root of a binary tree, determine if it is a complete binary tree.
In a complete binary tree, every level, except possibly the last, is completely filled, and all nodes in the last level are as far left as possible. It can have between 1 and 2h nodes inclusive at the last level h.
Example 1:
Input: root = [1,2,3,4,5,6]
Output: true
Explanation: Every level before the last is full (ie. levels with node-values {1} and {2, 3}), and all nodes in the last level ({4, 5, 6}) are as far left as possible.
Example 2:
Input: root = [1,2,3,4,5,null,7] Output: false Explanation: The node with value 7 isn't as far left as possible.
Constraints:
[1, 100].1 <= Node.val <= 1000