ARTS(2020-05-25/2020-05-31)

/**
 * 无重复字符的最长子串
 * https://leetcode-cn.com/problems/longest-substring-without-repeating-characters/
 *
 * 主要是使用滑动窗口的思想 时间复杂度O(n)
 */
public class Solution0003 {
    public int lengthOfLongestSubstring(String s) {
        int res = 0;
        Map<Character, Integer> map = new HashMap<>();
        for (int start = 0, end = 0; end < s.length(); end++) {
            char c = s.charAt(end);
            if (map.containsKey(c)) {
                start = Math.max(start, map.get(c));
            }
            res = Math.max(res, end - start + 1);
            map.put(c, end + 1);
        }
        return res;
    }
}