Function levelOrder

javascript/0102-binary-tree-level-order-traversal.js:8–13

(root)

 * @return {number[][]}
 */
var levelOrder = function (root) {
    const isBaseCase = root === null;
    if (isBaseCase) return [];

    return bfs([root]);
};

const bfs = (queue /* Space O(W) */, levels = []) => {
    while (queue.length) {