222. Count Complete Tree Nodes
Easy
10 Points
Binary Search
Bit Manipulation
Tree
Binary Tree
Given the root of a complete binary tree, return the number of the nodes in the tree.
According to Wikipedia, every level, except possibly the last, is completely filled in a complete binary tree, 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.
Design an algorithm that runs in less than O(n) time complexity.
Examples
Example 1
Input: root = [1,2,3,4,5,6]
Output: 6
Example 2
Input: root = []
Output: 0
Example 3
Input: root = [1]
Output: 1
Constraints
The number of nodes in the tree is in the range [0, 5 * 104].0 <= Node.val <= 5 * 104The tree is guaranteed to be complete.
222. Count Complete Tree Nodes
Easy
10 Points
Binary Search
Bit Manipulation
Tree
Binary Tree
Given the root of a complete binary tree, return the number of the nodes in the tree.
According to Wikipedia, every level, except possibly the last, is completely filled in a complete binary tree, 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.
Design an algorithm that runs in less than O(n) time complexity.
Examples
Example 1
Input: root = [1,2,3,4,5,6]
Output: 6
Example 2
Input: root = []
Output: 0
Example 3
Input: root = [1]
Output: 1
Constraints
The number of nodes in the tree is in the range [0, 5 * 104].0 <= Node.val <= 5 * 104The tree is guaranteed to be complete.