Solving NP-Complete Combinatorial Problem Using Multiple OBDDs

There exists a method using Ordered Binary Decision Diagrams (OBDDs) to solve combinatorial problems. In the method, Boolean variables are de ned and a Boolean function is constructed as an OBDD whose value is 1 for assignments which satisfy conditions of a problem. In this paper, we improve the method. As the values of almost all variables are xed before the construction of the OBDD, our algorithm can solve far larger instances than before.