public void MoveTo(SuffixNode node, int distanceFromNode)
{
CurrentNode = node;
Distance = distanceFromNode;
}
public SuffixTree()
{
Root = new SuffixNode(this);
}
public void MoveTo(SuffixNode node)
{
CurrentNode = node;
Distance = 0;
}
/// <summary>
/// Adds a new leaf at the current position (also a new branch, if we are not currently on a node),
/// and sets Next to the branch node (the leaf's parent).
/// </summary>
/// <returns>Whether the branch node already existed</returns>
protected bool AddBranch(int k)
{
var parent = LastNode;
if (Distance != 0)
{
// Adding branch between two nodes
var next = CurrentNode;
// split edge & add branch node
// (next also describes the edge between parent and next)
var branchNode = new SuffixNode(parent, next.From, next.From + Distance - 1);
parent.Children.Remove(next); // HashSet Add/Remove operations are constant
parent.Children.Add(branchNode);
branchNode.Children.Add(next);
next.Parent = branchNode;
next.From += Distance;
// branchNode becomes parent of the new leaf
parent = branchNode;
}
// else Add branch to existing node
// add new leaf
var leaf = new SuffixNode(parent, k);
parent.Children.Add(leaf);
#if DEBUG
Console.WriteLine(" Added leaf {0} {1}: {2}", leaf, Distance == 0 ? "to existing branch" : "to new branch", parent);
#endif
CurrentNode = parent;
return Distance == 0;
}
/// <summary>
/// Adds a new link
/// </summary>
private void AddLink(SuffixNode startNode, SuffixNode linkedNode)
{
#if DEBUG
Console.WriteLine(" Added link from {0} to {1}", startNode, linkedNode);
#endif
// link is only a simple pointer
var newLink = new SuffixLink
{
Node = linkedNode
};
Links.Add(startNode, newLink);
}
/// <summary>
/// Move to the link that the given branch links to
/// </summary>
/// <returns>The length of the substring for that link</returns>
private void MoveToLink(SuffixNode branch)
{
SuffixLink link;
if (Links.TryGetValue(branch, out link))
{
// Move to link and return saved length
MoveTo(link.Node);
#if DEBUG
Console.WriteLine(" Moved along link to: {0}", CurrentNode);
#endif
}
else if (CurrentNode != Tree.Root)
{
throw new SuffixTreeBuilderException("Unable to build SuffixTree: Internal node did not have a link: " + CurrentNode);
}
}
internal SuffixNode(SuffixNode parent, int from, int to) :
this(parent.Tree, from, to)
{
Parent = parent;
Parent.Children.Add(this);
}
/// <summary>
/// Ctor for leaves
/// </summary>
internal SuffixNode(SuffixNode parent, int from) :
this(parent, from, -1)
{
}