public class Solution {
    public int lengthOfLongestSubstring(String s) {
         HashMap hm=new HashMap();
         int len=s.length();
         if(len==0)
            return 0;
         int i,j;
         i=0;
         j=0;
         int max=1;
         hm.put(s.charAt(j),0);
         while(jmax)
                    max=j-i+1;
                 return max;
             }
             j=j+1;
             if(hm.containsKey(s.charAt(j))){
                 if(j-i>max){
                     max=j-i;
                 }
                 int newi=hm.get(s.charAt(j))+1;
                 for(int k=i;k