Store the scc_map_ as a vector instead of a std::map. There is no
point in using a map since the SCC are numbered in sequence. * src/tgbaalgos/scc.hh (scc_map::relabel_component): Return the number of the SCC instead of taking it as argument. (scc_map::scc_num_): Delete this variable. scc_map_.size() gives the same information. (scc_map::scc_map_type): Define using std::vector instead of std::map. * src/tgbaalgos/scc.cc: Adjust all uses.