大师兄

class TreeNode {
  constructor(value, left = null, right = null) {
    this.value = value;
    this.left = left;
    this.right = right;
  }
}

/**
 * 层级遍历二叉树
 * @param {TreeNode} root
 */
function levelTravel(root) {
  const queue = [root];
  while (queue.length) {
    let first = queue.shift();
    console.log(first.value);

    if (first.left) {
      queue.push(first.left);
    }

    if (first.right) {
      queue.push(first.right);
    }
  }
}

/**
 *
 */

const root = new TreeNode(
  10,
  new TreeNode(6, new TreeNode(4), new TreeNode(8)),
  new TreeNode(14, new TreeNode(12), new TreeNode(16))
);

levelTravel(root);