/// <summary>
/// Creates a suffix tree for the given text.
/// Make sure the last character in 'text' is unique; im using $..
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="text">The text.</param>
/// <returns>if the argument 'text' is empty or null string, function returns null !!</returns>
public static ISuffixTree Create <T>(string text)
where T : IDictionary <char, ISuffixNode>, new()
{
var suffixImpl = SuffixTreeImpl <T> .Create(text);
return(suffixImpl == null ? null : new SuffixTree()
{
Root = suffixImpl.Root, Text = suffixImpl.Text
});
}
public static SuffixTreeImpl <ChildrenCollectionType> Create(string text)
{
if (string.IsNullOrEmpty(text))
{
return(null);
}
var tree = new SuffixTreeImpl <ChildrenCollectionType>();
tree.Text = text;
var root = tree.theRoot;
int m = text.Length;
var deep = root.AddEdge(tree.Text, 0, -1);
deep.SetLeaf(0);
SuffixNode prevExtEnd = deep;
int lastCreatedLeaf = -1;
for (int i = 1; i < m; i++)
{
tree.CurrentPhase = i;
bool skipRemaining = false;
SuffixNode internCreatedPrevExt = null;
for (int j = 1; j < i && !skipRemaining; j++)
{
if (j < lastCreatedLeaf)
{
continue;
}
List <EdgeLabel> edges = null;
SuffixNode found = null;
int edgecursor = -1;
bool matchEndedAtNode;
if (j == lastCreatedLeaf && j > 1)
{
if (!prevExtEnd.IsLeaf)
{
edges = new List <EdgeLabel>(new EdgeLabel[] { EdgeLabel.Create(i - 1, i - 1) });
matchEndedAtNode = tree.Match(prevExtEnd, edges, out found, out edgecursor);
}
else
{
found = prevExtEnd;
matchEndedAtNode = true;
}
}
if (found == null)
{
SuffixNode target = null;
if (tree.PreMatch(prevExtEnd, out target, out edges))
{
edges = new List <EdgeLabel>(new EdgeLabel[] { EdgeLabel.Create(j, i - 1) });
matchEndedAtNode = tree.Match(tree.theRoot, edges, out found, out edgecursor);
}
else
{
if (edges != null)
{
matchEndedAtNode = tree.Match(target, edges, out found, out edgecursor);
}
else
{
found = target;
matchEndedAtNode = true;
}
}
}
else
{
matchEndedAtNode = true;
}
if (!matchEndedAtNode)
{
if (tree.Text[edgecursor] == tree.Text[i])
{
skipRemaining = true;
break;
}
else
{
var foundParent = found.Parent;
// there's no node here .. better create one..
foundParent.RemoveEdge(tree.GetCharFromIndex(found.Edge.Start));
// create new node..
var internalNode = foundParent.AddEdge(tree.Text, found.Edge.Start, edgecursor - 1);
// massage old node and add it back..
found.Parent = internalNode;
found.Edge.Start = edgecursor;
internalNode.AddEdge(tree.Text, found);
// fix up links if we need to ..
if (internCreatedPrevExt != null)
{
internCreatedPrevExt.Link = internalNode;
}
internCreatedPrevExt = internalNode;
// create a new leaf and hang it here..
var newLeaf = internalNode.AddEdge(tree.Text, i, -1);
newLeaf.SetLeaf(j);
lastCreatedLeaf = j;
prevExtEnd = internalNode;
}
}
else
{
if (found.IsLeaf)
{
prevExtEnd = found;
}
else
{
if (internCreatedPrevExt != null)
{
internCreatedPrevExt.Link = found;
}
internCreatedPrevExt = found.Link == null ? found : null;
if (found.GetEdge(tree.GetCharFromIndex(i)) == null)
{
var newLeaf = found.AddEdge(tree.Text, i, -1);
newLeaf.SetLeaf(j);
lastCreatedLeaf = j;
prevExtEnd = found;
}
else
{
skipRemaining = true;
break;
}
}
}
}
if (!skipRemaining)
{
var parent = root;
var child = parent.GetEdge(tree.GetCharFromIndex(i));
if (child == null)
{
var newLeaf = parent.AddEdge(tree.Text, i, -1);
newLeaf.SetLeaf(i);
lastCreatedLeaf = i;
prevExtEnd = newLeaf;
}
if (internCreatedPrevExt != null)
{
internCreatedPrevExt.Link = parent;
internCreatedPrevExt = null;
}
}
}
tree.FixupLeaves(tree.theRoot, tree.Text.Length - 1);
return(tree);
}
/// <summary>
/// Creates a suffix tree for the given text.
/// Make sure the last character in 'text' is unique; im using $..
/// </summary>
/// <param name="text">The text.</param>
/// <returns>if the argument 'text' is empty or null string, function returns null !!</returns>
public static ISuffixTree Create(string text)
{
return(SuffixTreeImpl <Dictionary> .Create(text));
}
/// <summary>
/// Creates a suffix tree for the given text.
/// Make sure the last character in 'text' is unique; im using $..
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="text">The text.</param>
/// <returns>if the argument 'text' is empty or null string, function returns null !!</returns>
public static ISuffixTree Create <T>(string text)
where T : IDictionary <char, ISuffixNode>, new()
{
return(SuffixTreeImpl <T> .Create(text));
}
