[Leetcode] [JavaScript] Count Complete Tree Nodes

Count Complete Tree Nodes

Given a complete binary tree, count the number of nodes.

Definition of a complete binary tree from Wikipedia:
In a complete binary tree every level, except possibly the last, was completely filled, and all nodes As far left as possible. It can has between 1 and 2hnodes inclusive at the last level H.

https://leetcode.com/problems/count-complete-tree-nodes/

Tricky approach, to the left to find the deepest leaf node, to the right to find the deepest leaf node.

If their depth is the same, the description is a complete binary tree, the node points are applied to the formula 2^n-1.

Otherwise, the same method is used to recursively Saozi the right sub-tree of this point.

2 of the cyclic conditions are written as while (Leftchild && leftchild.val), Val may be 0, the result is not orz.

1 /**2 * Definition for a binary tree node.3 * Function TreeNode (val) {4 * This.val = val;5 * This.left = This.right = null;6  * }7  */8 /**9 * @param {TreeNode} rootTen * @return {number} One  */ A varCountnodes =function(root) { -     returnTreeNodes (root); -  the     functiontreenodes (node) { -         if(!node) { -             return0; -}Else{ +             varleftdepth = 0; -             varrightdepth = 0; +             varLeftchild =Node.left; A              while(leftchild) { atleftdepth++; -Leftchild =Leftchild.left; -             } -             varRightchild =Node.right; -              while(rightchild) { -rightdepth++; inRightchild =Rightchild.right; -             } to             if(Leftdepth = = =rightdepth) { +                 returnMath.pow (2, leftdepth + 1)-1; -}Else{ the                 returnTreeNodes (Node.left) + treenodes (node.right) + 1; *             } $         }Panax Notoginseng     } -};

[Leetcode] [JavaScript] Count Complete Tree Nodes