摘要：
Given a binary tree, return the preorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3]. Note: Rec... 阅读全文
摘要：
Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in or... 阅读全文