public static SequenceInvertedIndex Build(InvertedIndex invindex, SequenceBuilder builder)
{
var newinvindex = new SequenceInvertedIndex ();
var xseq = new int[invindex.NumberOfItems];
for (int sym = 0; sym < invindex.Count; ++sym) {
var list = invindex [sym];
foreach (var objID in list) {
xseq [objID] = sym;
}
}
newinvindex.seq = builder.Invoke (xseq, invindex.Count);
return newinvindex;
}