4.17 leetcode -17 longest-substring-without-repeating-characters

题目描述

Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for "abcabcbb" is "abc", which the length is 3. For "bbbbb" the longest substring is "b", with the length of 1.

这个题目就比较有意思了，最小子串，里面不能包含重复的字符。

我觉得用桶（或者map）就能做.

class Solution {public:    int lengthOfLongestSubstring(string s) {        bool btong[255];        for(int i = 0;i < 255;i++)            btong[i] = false;                int nlength = s.length();        int start = 0;        int nmax = 0;        for(int i = 0;i < nlength;i++)            {            if(btong[s[i]] == false)                btong[s[i]] = true;            else                {                if((i-start) > nmax)                    nmax = (i-start);                while(s[start] != s[i])                    {                    btong[s[start]] = false;                    start ++;                }                start ++;            }        }        if((nlength-start) > nmax)           nmax = (nlength-start);       return nmax;    }};