# Graph orientations with no sink and an approximation for a hard case of #SAT

@inproceedings{Bubley1997GraphOW, title={Graph orientations with no sink and an approximation for a hard case of \#SAT}, author={Russ Bubley and Martin E. Dyer}, booktitle={SODA '97}, year={1997} }

Graph orientation problems have a long pedigree both in pure mathematics and theoretical computer science. We consider here all of the major combinatorial problems associated with sink-free graph orientations: decision, construction, listing, counting, approximate counting and approximate sampling. We also observe a close connection between sink-free graph orientations and a restricted form of the SAT problem in which each variable may appear at most twice; we name this Twice-SAT. We show that…

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