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Find Largest Value in Each Tree Row

Problem statement​

Given the root of a binary tree, return an array of the largest value in each row of the tree (0-indexed).

Example 1:

Input: root = [1,3,2,5,3,null,9]Output: [1,3,9]

Example 2:

Input: root = [1,2,3]Output: [1,3]

Constraints:

  • The number of nodes in the tree will be in the range [0, 104].
  • -231 <= Node.val <= 231 - 1

My solution​

/**
 * 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 largestValues = function(root) {
    let queue = [root];
    
    const max = [];
    
    if (!root) {
        return max;
    }
    
    while(queue.length > 0) {
        const level = [];
        let currentMax = Number.MIN_SAFE_INTEGER;
        
        for(const node of queue) {
            currentMax = Math.max(currentMax, node.val);
            
            if (node.left) {
                level.push(node.left)
            }
            
            if (node.right) {
                level.push(node.right);
            }
        }
        
        max.push(currentMax);
        queue = level;
    }
    
    return max;
};