protected virtual SNode getAt(string s)
{
int idx = key.Length;
if (children.Count < 1)
{
return(null);
}
SNode node = children.FirstOrDefault(ch => ch.key[idx] == s[idx]);
return(node == null ? null : idx == s.Length - 1 ? node : node.getAt(s));
}
public int FindNumOf(string pattern)
{
int idx = key.Length;
if (children.Count < 1)
{
return(0);
}
SNode node = children.FirstOrDefault(ch => ch.key[idx] == pattern[idx]);
return(node == null ? 0 : idx == pattern.Length - 1 ? node.size : node.FindNumOf(pattern));
}
public bool Add(string newKey, ref bool hasPrefix)
{
size++;
int idx = key.Length;
bool isLevel = idx == newKey.Length - 1;
SNode child = children.FirstOrDefault(ch => ch.key[idx] == newKey[idx]);
if (child != null)
{
if (child.children.Count() < 1)
{
hasPrefix = true;
}
return(isLevel ? !(hasPrefix = true) : child.Add(newKey, ref hasPrefix));
}
else
{
SNode newNode = new SNode {
key = newKey.Substring(0, idx + 1)
};
children.Add(newNode);
return(isLevel ? newNode.size++ == 0 : newNode.Add(newKey, ref hasPrefix));
}
}
