Solution Review: Finding All Words Stored in Trie

using System;
using System.Collections.Generic;
using System.Text;
namespace chapter_7
{
    class Program
    {
        static void getWords(TrieNode root, List<string>  result, int level, ref string word)
        {
            //Leaf denotes end of a word
            if (root.isEndWord)
            {
                //current word is stored till the 'level' in the word string
                string temp = "";
                for (int x = 0; x < level; x++)
                {
                    temp += word[x];
                }
                result.Add(temp);
            }
            for (int i = 0; i < 26; i++)
            {
                if (root.children[i] != null)
                {
                    if(level < word.Length)
                    {
                        StringBuilder sb = new StringBuilder(word);
                        sb[level] = (char)(i + 'a');
                        word = sb.ToString();
                    }
                    else
                    {
                        word += (char)(i + 'a');
                    }
                    getWords(root.children[i], result, level + 1, ref word);
                }
            }
        }
        static List<string> findWords(TrieNode root)
        {
            List<string> result = new List<string> () ;
            string word = "";
            getWords(root, result, 0,ref  word);
            return result;
        }
        static void Main(string[] args)
        {
            string [] keys = { "the", "a", "there", "answer", "any", "by", "bye", "their", "abc" };
            
            Trie t = new Trie();
            // Construct trie       
            for (int i = 0; i < 9; i++)
            {
                t.insertNode(keys[i]);
            }
            List<string> ans = findWords(t.getRoot());
            for (int i = 0; i < ans.Count; i++)
            {
                Console.WriteLine( ans[i] );
            }
            return;
        }
    }
}