RC Learning

题号：3 原题：Longest Substring Without Repeating CharactersGiven a string, find the length of the longest substring without repeating characters. // 给定一个字符串，找到最长子串，里面不能有重复的字符。 Examples:Given "abcabcbb",

原题描述： Given a binary tree, return the preorder traversal of its nodes' values. For example: Given binary tree{1,#,2,3}, 分析： 先序遍历，遍历顺序为：根节点 -> 左子树 -> 右子树 代码： /** * Definition for bi