// Delete is just to set the value to null.
private TernaryTrieNode <V> PutHelper(string key, V value, TernaryTrieNode <V> node, int d)
{
char charKey = key.ElementAt(d);
if (node == null)
{
node = new TernaryTrieNode <V> {
CharKey = charKey
};
}
var response = charKey.CompareTo(node.CharKey);
if (response < 0)
{
node.Left = PutHelper(key, value, node.Left, d);
}
else if (response > 0)
{
node.Right = PutHelper(key, value, node.Right, d);
}
else if (d < key.Length - 1)
{
node.Middle = PutHelper(key, value, node.Right, d + 1);
}
else
{
node.Value = value;
}
return(node);
}
// Search miss is the beauty here.
private TernaryTrieNode <V> GetHelper(string key, TernaryTrieNode <V> node, int d)
{
if (d == key.Length || node == null)
{
return(node);
}
char c = key.ElementAt(d);
var parent = node.Get(c);
return(GetHelper(key, parent, d + 1));
}
private int SearchTrie(string key, TernaryTrieNode <V> node, int d, int length)
{
if (node == null)
{
return(length);
}
if (node.Value != null)
{
length = d;
}
if (d == key.Length)
{
return(length);
}
char c = key.ElementAt(d);
var parent = node.Get(c);
return(SearchTrie(key, parent, d + 1, length));
}
private void TraverseTrie(TernaryTrieNode <V> node, Queue <string> output, StringBuilder builder)
{
if (node == null)
{
builder.Clear();
return;
}
builder.Append(node.CharKey);
if (node.Value != null)
{
output.Enqueue(builder.ToString());
}
else
{
foreach (var child in new[] { node.Left, node.Middle, node.Right })
{
TraverseTrie(child, output, builder);
}
}
}
public void put(string key, V value)
{
_root = PutHelper(key, value, _root, 0);
}