Design and search word

class WordDictionary { Trie t; public WordDictionary() { t = new Trie(); } public void addWord(String word) { t.insert(word); } public boolean search(String word) { return t.search(word); } } class Node{ Node[] root = new Node[26]; boolean end = false; public void add(char c, Node n){ root[c-'a'] = n; } public boolean present(char c){ return root[c-'a']!=null; } public Node get(char c){ return root[c-'a']; } public boolean isEnd(){ return end; } public void setEnd(){ this.end = true; } } class Trie{ Node root; public Trie(){ root = new Node(); } public void insert(String s){ Node node = root; for(int i=0;i<s.length();i++){ char c = s.charAt(i); if(!node.present(c)){ node.add(c,new Node()); } node = node.get(c); } node.setEnd(); } //present: world, search: w.rld public boolean search(String s){ Node node = root; return find(0,s,node); } public boolean find(int index, String s,Node n){ Node node = n; for(int j=index;j<s.length();j++){ char c = s.charAt(j); if(c=='.'){ for(int i =0;i<26;i++){ if(node.root[i]!=null && find(j+1,s,node.root[i])) return true; } return false; } else{ if(!node.present(c)) return false; node = node.get(c); } } return node.isEnd(); } }