摘要： Example1: x = 123, return 321Example2: x = -123, return -321 click to show spoilers.Have you thought about this?Here are some good questions to ask be... 阅读全文

摘要： Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.Subscribe to see which com... 阅读全文

摘要： Given a binary tree, return all root-to-leaf paths.For example, given the following binary tree: 1 / \2 3 \ 5All root-to-leaf paths are:["1->... 阅读全文