public class TrieNode {
        char value;
        boolean isLast;
        Map<Character, TrieNode> next = new HashMap<>();
        
        public TrieNode(char value, boolean isLast) {
            this.value = value;
            this.isLast = isLast;
        }
    }
    
    public static void noPrefix(List<String> words) {
        TrieNode root = new Result().new TrieNode('z', false);
        for (String word: words) {
            TrieNode node = root;
            for (int i = 0; i < word.length(); i++) {
                char c = word.charAt(i);
                TrieNode temp = new Result().new TrieNode(c, i == word.length() -1 ? true : false);
                
                if(!node.next.containsKey(c)) {
                    node.next.put(c, temp);
                } else {
                    temp = node.next.get(c);
                    temp.isLast = temp.isLast || i == (word.length() - 1);
                    
                    if(temp.isLast) {
                        System.out.println("BAD SET");
                        System.out.println(word);
                        return;
                    }
                } 
                node = temp;
            }
        }
        System.out.println("GOOD SET");
    }