[LeetCode]--3. Longest Substring Without Repeating Characters

Given a string, find the length of the longest substring without repeating characters.

Examples:

Given “abcabcbb”, the answer is “abc”, which the length is 3.

Given “bbbbb”, the answer is “b”, with the length of 1.

Given “pwwkew”, the answer is “wke”, with the length of 3. Note that the answer must be a substring, “pwke” is a subsequence and not a substring.

这个题目我昨晚上一下子没有做出来，看了别人的参考之后，早上来到实验室搞定了，应该算是掌握了吧，下面是我自己贴的代码，仅供参考哈。

public int lengthOfLongestSubstring(String s) {
        if (s == null || s.length() ==