private int Search(TernaryTrieNode <TValue> node, string query, int levelCounter, int prefixLength)
{
if (node == null)
{
return(prefixLength);
}
char character = query[levelCounter];
if (character < node.Character)
{
return(Search(node.Left, query, levelCounter, prefixLength));
}
else if (character > node.Character)
{
return(Search(node.Right, query, levelCounter, prefixLength));
}
else
{
if (node.IsNodeValueSet)
{
prefixLength = levelCounter;
}
return(Search(node.Middle, query, levelCounter + 1, prefixLength));
}
}
private TernaryTrieNode <TValue> Get(TernaryTrieNode <TValue> node, string key, int levelCounter)
{
if (node == null)
{
return(null);
}
var character = key[levelCounter];
if (character < node.Character)
{
return(Get(node.Left, key, levelCounter));
}
else if (character > node.Character)
{
return(Get(node.Right, key, levelCounter));
}
else if (levelCounter < key.Length - 1)
{
return(Get(node.Middle, key, levelCounter + 1));
}
else
{
return(node);
}
}
private TernaryTrieNode <TValue> Put(TernaryTrieNode <TValue> node, string key, TValue value, int levelCounter)
{
var character = key[levelCounter];
if (node == null)
{
node = new TernaryTrieNode <TValue>(character);
}
if (character < node.Character)
{
node.Left = Put(node.Left, key, value, levelCounter);
}
else if (character > node.Character)
{
node.Right = Put(node.Right, key, value, levelCounter);
}
else if (levelCounter < key.Length - 1)
{
node.Middle = Put(node.Middle, key, value, levelCounter + 1);
}
else
{
if (!node.IsNodeValueSet)
{
Size++;
}
node.Value = value;
}
return(node);
}
private void Collect(TernaryTrieNode <TValue> node, string prefix, IList <string> queue)
{
if (node == null)
{
return;
}
Collect(node.Left, prefix, queue);
char character = node.Character;
if (node.IsNodeValueSet)
{
queue.Add(prefix + character);
}
Collect(node.Middle, prefix + character, queue);
Collect(node.Right, prefix, queue);
}
private static void SetChildToNull(TernaryTrieNode <TValue> parent, TernaryTrieNode <TValue> child)
{
if (parent == null)
{
return;
}
if (parent.Left == child)
{
parent.Left = null;
}
if (parent.Middle == child)
{
parent.Middle = null;
}
if (parent.Right == child)
{
parent.Right = null;
}
}
private TernaryTrieNode <TValue> Delete(TernaryTrieNode <TValue> node, string key, int levelCounter)
{
if (node == null)
{
return(null);
}
var character = key[levelCounter];
if (character < node.Character)
{
var childNode = Delete(node.Left, key, levelCounter);
if (childNode != null && IsNodeEmpty(childNode))
{
SetChildToNull(node, childNode);
}
return(node);
}
else if (character > node.Character)
{
var childNode = Delete(node.Right, key, levelCounter);
if (childNode != null && IsNodeEmpty(childNode))
{
SetChildToNull(node, childNode);
}
return(node);
}
else if (levelCounter < key.Length - 1)
{
var childNode = Delete(node.Middle, key, levelCounter + 1);
if (childNode != null && IsNodeEmpty(childNode))
{
SetChildToNull(node, childNode);
}
return(node);
}
else
{
node.ClearNodeValue();
Size--;
return(node);
}
}
private static bool IsNodeHaveNoChildren(TernaryTrieNode <TValue> node)
{
return(node.Left == null && node.Middle == null && node.Right == null);
}
private static bool IsNodeEmpty(TernaryTrieNode <TValue> node)
{
return(!node.IsNodeValueSet && IsNodeHaveNoChildren(node));
}
