LeetCode Word Ladder

public class Solution {
    public int ladderLength(String beginWord, String endWord, Set<String> wordList) {
        if(beginWord == null || beginWord.length() == 0 || endWord == null || endWord.length() == 0 || beginWord.length() != endWord.length()){
            return 0;
        }
        int level = 1;
        int curCount = 1;
        int nextCount = 0;
        LinkedList<String> wordQue = new LinkedList<String>();
        wordQue.offer(beginWord);
        while(!wordQue.isEmpty()){
            String cur = wordQue.poll();
            curCount--;
            
            for(int i = 0; i<cur.length(); i++){
                char [] curToChar = cur.toCharArray();
                for(char k = ‘a‘; k<=‘z‘; k++){
                    curToChar[i] = k;
                    String check = new String(curToChar);
                    if(check.equals(endWord)){
                        return level+1;
                    }
                    if(wordList.contains(check)){
                        wordQue.offer(check);
                        nextCount++;
                        wordList.remove(check);
                    }
                }
            }
            
            if(curCount == 0){
                level++;
                curCount = nextCount;
                nextCount = 0;
            }
        }
        return 0;
    }
}