/// <summary>
/// Creates the suffix array in O(n) time from the given text.
/// The last character in argument 'text' must be the unique $ char. see remarks..
/// </summary>
/// <param name="text">The text.</param>
/// <returns>
/// $ happens to sort nicely in front of other normal chars.. so reversing the children collection when parsing the tree to build up the suffix array just works
/// small change if you need to terminate your text with other unique char..
/// </returns>
public static int[] Create(string text)
{
var suffixTree = SuffixTree.Create <SortedList>(text);
if (suffixTree != null)
{
return(Create(suffixTree));
}
else
{
return(null);
}
}
/// <summary>
/// Computes the BurrowsWheelerTransform in O(n) time..
/// </summary>
/// <param name="text">The text.</param>
/// <returns></returns>
public static string Build(string text)
{
if (string.IsNullOrEmpty(text))
{
return(string.Empty);
}
var suffixTree = SuffixTree.Create <SortedList>(text);
var suffixArray = SuffixArray.Create(suffixTree);
var bwt = new StringBuilder();
for (int k = 0; k < suffixArray.Length; ++k)
{
bwt.Append(suffixArray[k] != 0 ? text[suffixArray[k] - 1] : text[text.Length - 1]);
}
return(bwt.ToString());
}
private static void CreateSuffixTree(string text)
{
Console.Write(".");
Debug.WriteLine("");
Debug.WriteLine("");
Debug.WriteLine("");
Debug.WriteLine("================================================================================================= ");
Debug.WriteLine(text);
Debug.WriteLine("");
Debug.WriteLine("text length: {0}", text.Length);
Stopwatch stopWatch = new Stopwatch();
stopWatch.Start();
var t = SuffixTree.Create <SortedList>(text);
stopWatch.Stop();
Debug.WriteLine("total milliseconds: {0}", stopWatch.ElapsedMilliseconds);
Diagnose(t);
}
/// <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(SuffixTree.Create <Dictionary>(text));
}