public class Solution {
public int ladderLength(String beginWord, String endWord, Set
wordList) {
Queue q = new LinkedList<>();
q.add(beginWord);
wordList.remove(beginWord);
int level = 1;
while(!q.isEmpty()){
int size = q.size();
for(int i = 0; i < size; i++){
String s = q.remove();
for(int j = 0; j < s.length(); j++){
for(char c = 'a'; c <= 'z'; c++){
char[] cc = s.toCharArray();//start from the
original string
cc[j] = c;
String next = new String(cc);
if(next.equals(endWord)){
return level + 1;
}else if(wordList.contains(next)){
q.add(next);
wordList.remove(next);
}
}
}
}
level++;
}
return 0;
}
}
