[Leetcode]003. Longest Substring Without Repeating Characters

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

public class Solution {
    public int lengthOfLongestSubstring(String s) {

        if(s.length() == 0 )return 0;
        HashMap<Character,Integer> map = new HashMap<Character, Integer>();
        int max = 0;
        int j = 0;
        for(int i=0;i<s.length();i++){
            if(map.containsKey(s.charAt(i))){
                j=Math.max(j,map.get(s.charAt(i))+1);
            }
            map.put(s.charAt(i),i);
            max = Math.max(max,i-j+1);
        }
        return max;

    }
}