3. Longest Substring Without Repeating Characters(无重复字符的最长子串)

Input: "abcabcbb"
Output: 3 
Explanation: The answer is "abc", with the length of 3. 

Input: "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.

Input: "pwwkew"
Output: 3
Explanation: 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.

输入: "abcabcbb"
输出: 3 
解释: 无重复字符的最长子串是 "abc"，其长度为 3。

输入: "bbbbb"
输出: 1
解释: 无重复字符的最长子串是 "b"，其长度为 1。

输入: "pwwkew"
输出: 3
解释: 无重复字符的最长子串是 "wke"，其长度为 3。
     请注意，答案必须是一个子串，"pwke" 是一个子序列 而不是子串。

class Solution {
        public int lengthOfLongestSubstring(String s) {
        char[] c = s.toCharArray();
        List<Character> list = new LinkedList<Character>();
        int max = 0;
        for (int i = 0; i < c.length; ++i) {
            if (list.contains(c[i])) {
                max = Math.max(max, list.size());
                list.remove(0);
                while (list.contains(c[i])) {
                    list.remove(0);
                }
                list.add(c[i]);
            } else {
                list.add(c[i]);
            }
        }
        max = Math.max(max, list.size());
        return max;
    }
}

class Solution {
        public int lengthOfLongestSubstring(String s) {
        char[] c = s.toCharArray();
        List<Character> list = new LinkedList<Character>();
        int max = 0;
        for (int i = 0; i < c.length; ++i) {
            if (list.contains(c[i])) {
                max = Math.max(max, list.size());
                list.remove(0);
                while (list.contains(c[i])) {
                    list.remove(0);
                }
                list.add(c[i]);
            } else {
                list.add(c[i]);
            }
        }
        max = Math.max(max, list.size());
        return max;
    }
}

public class MainClass {
    public static String stringToString(String input) {
        return JsonArray.readFrom("[" + input + "]").get(0).asString();
    }
    
    public static void main(String[] args) throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        String line;
        while ((line = in.readLine()) != null) {
            String s = stringToString(line);
            
            int ret = new Solution().lengthOfLongestSubstring(s);
            
            String out = String.valueOf(ret);
            
            System.out.print(out);
        }
    }
}