力扣-3-无重复字符的最长子串

public int lengthOfLongestSubstring(String s) {
    if(s == null || s.length() == 0)   return 0;
    HashMap<Character,Integer> window = new HashMap<>();

    int max = 0;
    int left = 0,right = 0;
    while(right < s.length()){
        char c = s.charAt(right);
        right ++;
        window.put(c,window.getOrDefault(c,0)+1);

        System.out.println("window:["+left+","+right+")");

        while(window.get(c) > 1){//不含重复字符
            char d = s.charAt(left);
            left++;
            window.put(d,window.getOrDefault(d,0)-1);
        }
        max = Math.max(max,right - left);
    }

    return max;
}