Counting and Enumerating Independent Sets with Applications to Knapsack Problems

We introduce methods to count and enumerate all maximal independent, all maximum independent sets, and all independent sets in threshold graphs and k-threshold graphs. Within threshold graphs and k-threshold graphs independent sets correspond to feasible solutions in related knapsack instances. We give several characterizations for knapsack instances and multidimensional knapsack instances which allow an equivalent graph. This allows us to solve special knapsack instances as well as special multidimensional knapsack instances for fixed number of dimensions in polynomial time. We also conclude lower bounds on the number of necessary bins within several bin packing problems.