Longest Substring Without Repeating Characters

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

Example

For example, the longest substring without repeating letters for"abcabcbb"is"abc", which the length is3.

For"bbbbb"the longest substring is"b", with the length of1.

Note

最大没有重复字符的滑动窗口，没出现过就一直右边界增加，左边移动的时候再把出现的置回0

Code

public class Solution {
    /**
     * @param s: a string
     * @return: an integer
     */
    public int lengthOfLongestSubstring(String s) {
        // write your code here
        int[] set = new int[256];
        int res = 0, len = s.length();

        int j = 0;
        for (int i = 0; i < len; i++) {
            while (j < len && set[s.charAt(j)] == 0) {
                set[s.charAt(j)]++;
                j++;
            }

            res = Math.max(res, j - i);
            set[s.charAt(i)] = 0;
        }

        return res;
    }
}