package LeetCode;

/**
 * 題目：
 *      Given a string, find the length of the longest substring without repeating characters.
 *      Example 1:
 *          Input: "abcabcbb"
 *          Output: 3
 *          Explanation: The answer is "abc", with the length of 3.
 *      Example 2:
 *          Input: "bbbbb"
 *          Output: 1
 *          Explanation: The answer is "b", with the length of 1.
 *      Example 3:
 *          Input: "pwwkew"
 *          Output: 3
 *          Explanation: The answer is "wke", with the length of 3.
 *      Note that the answer must be a substring, "pwke
 */
public class LengthOfLongestSubstring_03_1009 {
    public int LengthOfLongestSubstring(String s){
        String result = "";//存放最長的字串
        String temp = "";
        int tail = 0;

        while (tail < s.length()) {
            if (!temp.contains(s.charAt(tail) + "")) {
                temp += s.charAt(tail);
                tail++;

                if (temp.length() > result.length()) {
                    result = temp;
                }
            }
            else {
                temp = temp.substring(1);
            }
        }
        return result.length();
    }

    public static void main(String[] args) {
        String s = "pwwkew";

        LengthOfLongestSubstring_03_1009 test = new LengthOfLongestSubstring_03_1009();
        int result = test.LengthOfLongestSubstring(s);
        System.out.println(result);
    }
}