public class Solution {
    public int ladderLength(String start, String end, HashSet<String> dict) {

        if (dict.size() == 0)
            return 0;

        LinkedList<String> wordQueue = new LinkedList<String>();
        LinkedList<Integer> distanceQueue = new LinkedList<Integer>();

        wordQueue.add(start);
        distanceQueue.add(1);


        while(!wordQueue.isEmpty()){
            String currWord = wordQueue.pop();
            Integer currDistance = distanceQueue.pop();

            if(currWord.equals(end)){
                return currDistance;
            }

            for(int i=0; i<currWord.length(); i++){
                char[] currCharArr = currWord.toCharArray();
                for(char c='a'; c<='z'; c++){
                    currCharArr[i] = c;

                    String newWord = new String(currCharArr);
                    if(dict.contains(newWord)){
                        wordQueue.add(newWord);
                        distanceQueue.add(currDistance+1);
                        dict.remove(newWord);
                    }
                }
            }
        }

        return 0;
    }
}