avg-of-levels-of-binary-tree.js

/* Average of Levels in Binary Tree

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].

Example 2:
Input: root = [3,9,20,15,7]
Output: [3.00000,14.50000,11.00000]
 
Constraints:
The number of nodes in the tree is in the range [1, 104].
-231 <= Node.val <= 231 - 1
*/

/**
 * Definition for a binary tree node.
 * function TreeNode(val, left, right) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.left = (left===undefined ? null : left)
 *     this.right = (right===undefined ? null : right)
 * }
 */

/**
 * @param {TreeNode} root
 * @return {number[]}
 */
 var averageOfLevels = function(root) {
    let avgs = [];
    let queue = [];
    
    if(root === null){
        return avgs;
    }
    
    queue.push(root);
    
    while(queue.length > 0){
        let n = queue.length;
        let temp = 0;
        let nos = n;
        while(n > 0){
            let curr = queue.shift();
            temp += curr.val;
            if(curr.left){
                queue.push(curr.left);
            }

            if(curr.right){
                queue.push(curr.right)
            }
            n--;
        }
        avgs.push(temp / nos);
    }

    return avgs;    
};