/// <summary>
/// Create a new Trie instance.
/// </summary>
/// <param name="rootTrieNode">The root TrieNode.</param>
internal Trie(TrieNode rootTrieNode)
{
this.RootTrieNode = rootTrieNode;
}
/// <summary>
/// Recursive method to get all the words starting from given TrieNode.
/// </summary>
private void GetWords(TrieNode trieNode, ICollection<string> words, StringBuilder buffer)
{
if (trieNode.IsWord)
{
words.Add(buffer.ToString());
}
foreach (var child in trieNode.Children.Values)
{
buffer.Append(child.Character);
this.GetWords(child, words, buffer);
// Remove recent character
buffer.Length--;
}
}
/// <summary>
/// Recursive method to add word. Gets the first char of the word,
/// creates the child TrieNode if null, and recurses with the first
/// char removed from the word. If the word length is 0, return.
/// </summary>
private void AddWord(TrieNode trieNode, char[] word)
{
if (word.Length == 0)
{
trieNode.IsWord = true;
trieNode.WordCount++;
}
else
{
var firstLetter = Utilities.FirstChar(word);
TrieNode child;
trieNode.Children.TryGetValue(firstLetter, out child);
if (child == null)
{
child = TrieFactory.GetTrieNode(firstLetter);
trieNode.Children[firstLetter] = child;
}
var firstLetterRemoved = Utilities.FirstCharRemoved(word);
this.AddWord(child, firstLetterRemoved);
}
}
