I have implemented the Burrows-Wheeler Transform as below:
eofChar = FromCharacterCode[255];BurrowsWheelerTransform[string_] := With[{s = string <> eofChar}, StringJoin @@ (StringPart[#, -1] & /@ Sort[NestList[ StringRotateLeft[#, 1] &, s, StringLength[s] - 1] , LexicographicOrder])]InverseBurrowsWheelerTransform[string_] := With[{len = StringLength[string], c = Characters[string]}, StringJoin @@ Most[SelectFirst[Nest[ SortBy[Transpose[Prepend[Transpose[#], c]], s |-> StringJoin @@ s, LexicographicOrder] &, {}, len], #[[-1]] == eofChar &]] ]bwt = BurrowsWheelerTransform["swiss miss is on a mission to mississippi"](*"nssaosn ss mwmsmp oot ipississsiiiiiÿ si"*)InverseBurrowsWheelerTransform[bwt](*"swiss miss is on a mission to mississippi"*)However, this implementation is very slow for larger strings especially in the inverse transform. I suspect this is due to all this Transpose business with column insertion. Is there a better way to implement this?