word to word

Question:

For each word, you can get a list of neighbor words by calling getWords(String), find all the paths from word1 to word2.

 public class Solution {
     List<List<String>> finalList = new ArrayList<>();

     public static void main(String[] args) {
         Solution s = new Solution();
         System.out.println(s.getPath("face", "book"));
     }

     public List<List<String>> getPath(String s, String e) {
         List<String> list = new ArrayList<String>();
         helper(s, e, list, new HashSet<String>());
         return finalList;
     }

     public void helper(String s, String e, List<String> list, Set<String> set) {
         if (set.contains(s) || (list.size() !=  && list.get(list.size() - ).equals(e))) return;
         list.add(s);
         set.add(s);

         if (s.equals(e)) {
             finalList.add(new ArrayList<String>(list));
         }

         List<String> dicts = getWords(s);
         for (String str : dicts) {
             helper(str, e, list, set);
         }

         list.remove(s);
         set.remove(s);
     }

     public List<String> getWords(String str) {
         List<String> list1 = new ArrayList<String>();

         if (str.equals("face")) {
             list1.add("foce");
             list1.add("fack");
         } else if (str.equals("foce")) {
             list1.add("face");
             list1.add("fook");
         } else if (str.equals("fack")) {
             list1.add("fook");
             list1.add("faok");
         } else if (str.equals("fook")) {
             list1.add("fack");
             list1.add("book");
         } else if (str.equals("faok")) {
             list1.add("foce");
             list1.add("book");
         }
         return list1;
     }
 }