private void BuildTrier(string[] words)
{
Root = new TrierNode(' ');
foreach (var word in words)
{
var current = Root;
foreach (var wc in word)
{
if (!current.Children.ContainsKey(wc))
{
current.Children[wc] = new TrierNode(wc);
}
current = current.Children[wc];
}
current.IsEndingChar = true;
}
}
public bool Query(char letter)
{
TrierNode longest = null;
while (current != null)
{
if (current.Children.TryGetValue(letter, out TrierNode child))
{
if (longest == null)
{
longest = child;
}
if (child.IsEndingChar)
{
current = longest;
return(true);
}
}
current = current.Fail;
}
current = longest ?? trier.Root;
return(false);
}
public StreamChecker(string[] words)
{
// build trier and fail pointer
trier = new Trier(words);
current = trier.Root;
}