implement FrontierSearch() in C++
implement GraphSet.subgraph() in python, but it has some known errors.
- subsetting method still has bugs on variable ordering in c++
- GraphSet.subgraph() needs more tests
add how_many_turns() and fix a bug in graphilliion.tutorial
update src/subsetting/
add max_elem() in zdd.cc to follow the update of subsetting
remove unused files from src/subsetting
rename src/pysetset to src/pygraphillion
suppress warnings in graphset_subgraph() in pygraphillion.cc
modify test/graphset.cc
- divide into small test functions
- run clique test on a larger clique graph
- for shrinking the universe, run clique test before others
rename clique() to cliques() in test/graphset.cc
compress test/graphset.cc
minimize() and maximize() accept weights as an argument
merge supergraphs() into include()
- include() accepts a GraphSet and a graph, like supergraphs()
- remove supergraphs()