"example_text": "Input: nums = [2,7,11,15], target = 9\nOutput: [0,1]\nExplanation: Because nums[0] + nums[1] == 9, we return [0, 1].", "A really brute force way ...
* Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level).