public class WordDictionary {    public class TrieNode{        TrieNode[] childs;        boolean hasWord;        public TrieNode(){            childs = new TrieNode[26];            hasWord = false;        }    }        TrieNode root;        public WordDictionary(){        root = new TrieNode();    }    // Adds a word into the data structure.    public void addWord(String word) {        TrieNode cur = root;        for (char c : word.toCharArray()){            if (cur.childs[c-‘a‘]==null){                cur.childs[c-‘a‘] = new TrieNode();            }            cur = cur.childs[c-‘a‘];        }        cur.hasWord = true;    }    // Returns if the word is in the data structure. A word could    // contain the dot character ‘.‘ to represent any one letter.    public boolean search(String word) {        return searchRecur(root,word,0);    }        public boolean searchRecur(TrieNode curNode, String word, int start){        if (curNode==null){            return false;        }                if (start>=word.length()){            return curNode.hasWord;        }                char c = word.charAt(start);        if (c==‘.‘){            for (TrieNode child : curNode.childs)                if (searchRecur(child,word,start+1)){                    return true;                }            return false;        } else {            return searchRecur(curNode.childs[c-‘a‘],word,start+1);        }    }}// Your WordDictionary object will be instantiated and called as such:// WordDictionary wordDictionary = new WordDictionary();// wordDictionary.addWord("word");// wordDictionary.search("pattern");