/// <summary>
/// Creates a new suffix trie.
/// </summary>
public SuffixTrie()
{
// The root represents a special terminator character
root = new TrieNode(0);
lastCode = 0;
}
/// <summary>
/// Recursively updates the trie, given the current size (not counting the root)
/// of the trie. To avoid generating unnecessary garbage, we pass a start index
/// into key.
/// </summary>
/// <param name="key">the key to lookup/update, relative to <see cref="startIndex"/></param>
/// <param name="startIndex">start location into <see cref="key"/></param>
/// <param name="nextCode">the next code to be assigned</param>
public void Update(byte[] key, int startIndex, ref uint nextCode)
{
// string is already known or a substring of a known string
if (startIndex >= key.Length) { return; }
byte navigateChar = key[startIndex];
TrieNode nextNode;
// if the byte is not already known
if (!children.TryGetValue(navigateChar, out nextNode))
{
nextNode = new TrieNode(++nextCode);
children.Add(navigateChar, nextNode);
}
nextNode.Update(key, startIndex + 1, ref nextCode);
}