> Update: Sux4j has some interesting implementations of fast select/rank If you are using C++ you can have a look at my library of succinct data structures: h

> Update: Sux4j has some interesting implementations of fast select/rank If you are using C++ you can have a look at my library of succinct data structures: https://github.com/ot/succinct https://github.com/ot/succinct It uses the same algorithms as Sux4j for rank/select (https://github.com/ot/succinct/blob/master/rs_bit_vector.hpp https://github.com/ot/succinct/blob/master/rs_bit_vector.hpp) but it has exhaustive unit tests and the resulting files can be memory-mapped instead of loaded in memory, which has a number of advantages. I'm also going to release soon an optimized implementation of wavelet trees (actually a more generic variant that we are developing).