3. Longest Substring Without Repeating Characters java

https://leetcode.com/problems/longest-substring-without-repeating-characters/

Longest Substring Without Repeating Characters - LeetCode

Queue를 이용한 풀이

class Solution {
        public static int lengthOfLongestSubstring(String s) {
        Queue<Character> q = new LinkedList<>();
        int maxLen = 0;
        for(int i=0 ; i<s.length() ; i++){

            while(q.contains(s.charAt(i))) {
                maxLen = Math.max(maxLen, q.size());
                q.poll();
            }

            q.add(s.charAt(i));
            maxLen = Math.max(maxLen, q.size());
        }
        return maxLen;
    }
}

HashMap을 이용한 풀이

class Solution {
    public int lengthOfLongestSubstring(String s) {
        int maxLen = 0;
        int i,j=0;
        Map<Character,Integer> charMap = new HashMap<Character,Integer>();

        for(i =0;i<s.length();i++) {
            while(charMap.containsKey(s.charAt(i))) {
                maxLen=Math.max(maxLen,charMap.size());
                charMap.remove(s.charAt(j++));
            }
            charMap.put(s.charAt(i),i);
        }
        maxLen=Math.max(maxLen,charMap.size());
        return maxLen;
    }
}