xml和json互转

1、无重复字符的最长子串

自己用java实现的算法

public int lengthOfLongestSubstring(String s) {
        int length = 0;
        char[] chars = s.toCharArray();

        Map<Character, Set<Character>> map = new LinkedHashMap<>();
        for (int i = 0; i < chars.length; i++) {
            char c = chars[i];
            Set<Character> set = new HashSet<>();
            for (int j = i; j < chars.length; j++) {
                char cj = chars[j];
                if (!set.contains(cj)) {
                    set.add(cj);
                } else {
                    break;
                }
            }
            if (map.get(c) == null || map.get(c).size() < set.size()) {
                map.put(c, set);
            }
        }

        for (Map.Entry<Character, Set<Character>> entry : map.entrySet()) {
            int lengthTmp = entry.getValue().size();
            if (lengthTmp >= length) {
                length = lengthTmp;
            }
        }
        return length;
    }

2、