/**

* code by : 老王

* https://github.com/simplemain

*/

public class Solution4

{

public static void main(String[] args)

{

final String s = "abcabcbb";

final Solution sol = new Solution4().new Solution();

final int result = sol.lengthOfLongestSubstring(s);

System.out.printf("%d\n", result);

}

class Solution

{

public int lengthOfLongestSubstring(String s)

{

final int len = s.length();

final char[] cs = s.toCharArray();

int maxLen = 0;

final boolean[] exists = new boolean[256];

int curLen = 0;

int left = 0;

for (int right = 0; right < len; right++)

{

final char c = cs[right];

if (exists[c])

{

for (int j = left; j < right; j++)

{

exists[cs[j]] = false;

curLen--;

if (cs[j] == c)

{

left = j + 1;

break;

}

}

}

exists[c] = true;

curLen++;

if (curLen > maxLen)

{

maxLen = curLen;

}

}

return maxLen;

}

}

}