import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.Stack;/*** Created by ${chixiu} on 17/11/10.*/
public class TriedStr {public static void main(String[] args) {String[] worlds = new String[]{"d","do","dog","p","pe","pen","peng","pengu","pengui","penguin","e","el","ele","elep","eleph","elepha","elephan","elephant"};longestWord(worlds);System.out.println("TriedStr.main "+longestWord(worlds));}public static  String longestWord(String[] words) {Node root = new Node();int i=0;for(String sl :words){sert( sl, i, root );i++;}return findF(root,words);}static class Node{int index=-1;Map<Character,Node> map = new HashMap<Character,Node>();}public static String findF(Node root,String[] words){Node cur = root;String ans="";Stack<Node>  stack = new Stack<>();stack.push(cur);while(!stack.empty()){Node node = stack.pop();if(node == root){for( Map.Entry<Character,Node> entrySet:node.map.entrySet()){stack.push(entrySet.getValue());}}else{if(node.index <0){continue;}String word = words[node.index];if (word.length() > ans.length() ||word.length() == ans.length() && word.compareTo(ans) < 0) {ans = word;}for( Map.Entry<Character,Node> entrySet:node.map.entrySet()){if(entrySet.getValue().index <0){continue;}stack.push(entrySet.getValue());}}}return ans;}public static void  sert(String str,int index,Node root ){Node cur = root;for(Character character:str.toCharArray()){Node node = cur.map.get(character);if( node == null){node = new Node();cur.map.put(character,node);}cur = node;}cur.index=index;}
}