SPFA, ///< Using SPFA-SLF (Shortest Path Fast Algorithm with Short Label First) finding a shortest path.
SPFA_DOUBLE_WAY, ///< Using SPFA-SLF double way. It might not find shortest, but will use less memory.
SPFA, ///< Using SPFA-SLF (Shortest Path Fast Algorithm with Short Label First) finding a shortest path.
SPFA_DOUBLE_WAY, ///< Using SPFA-SLF double way. It might not find shortest, but will use less memory.