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.

unsight char 的范围是 0-255.

char 的范围是-128-127.

char *s 表示的是一个指针数组。

int lengthOfLongestSubstring(char* s) 
{
   bool flag[256];
   int  max =0;
   int  len   = strlen(s);
   int  i = 0, j= 0;
   for(int m = 0; m < 256 ; m++)
   {
       flag[m] = false;
   }
   while((i < len)&&(j < len))
   {
       if(!flag[s[j]])
       {
           flag[s[j]] = true;
           max = ((j-i+1)>max)?(j-i+1):max;
           j++;
       }
       else
       {
           flag[s[i]] = false;
           i++;
       }
   }
    return  max;
}