If you’re solving problems randomly… you’re wasting time. Top engineers don’t memorize problems. They recognize patterns.

* Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level).

//Runtime: 8 ms, faster than 99.49% of C++ online submissions for Validate Binary Search Tree. //Memory Usage: 22.2 MB, less than 5.05% of C++ online submissions for ...