java - Anagrams lintcode -

given array of strings, return groups of strings anagrams.

given ["lint", "intl", "inlt", "code"], return ["lint", "inlt", "intl"].

given ["ab", "ba", "cd", "dc", "e"], return ["ab", "ba", "cd", "dc"].

my code gave error msg @ "stringb.add(astring));"; couldn4t figure out why.

{     /**      * @param strs: list of strings      * @return: list of strings      */      private int hash(int[] count){         int hash = 0;         int primea = 378551;         int primeb = 378559;         //int result = 0;         for(int anumber: count){             hash = hash*primea + anumber;             primea = primea*primeb;         }     }      public list<string> anagrams(string[] strs) {         // write code here         int = 0;         int l = 0;         arraylist<string> result = new arraylist<string>();         map<integer, arraylist<string>> strings  = new hashmap<integer, arraylist<string>>();          for(string astring : strs){             int[] charcount = new int[26];             for(i = 0; i<astring.length(); i++){                 charcount[astring.charat[i]-'a']++;             }             l = hash(charcount);             if(!strings.containskey(l)){                 strings.put(l,new arraylist<string>());             }             arraylist<string> stringb = strings.get(l);             stringb.add(astring));          }         for(arraylist<string> alist: strings.values()){                 if(alist.size()>1){                     result.addall(alist);                 }         }         result result;     } }