Straddles and the Dantzig–Wolfe Bound of Cardinality-Indexed Knapsack Formulations
Many integer programs assign indivisible items to capacitated resources, each contributing a knapsack constraint with a setup variable. Cardinality-indexed formulations copy the variables of each resource once for every number of items it may serve; they have been used for generalized assignment, concentrator location, capacitated Steiner arborescence and unsplittable network design. We characterize when their … Read more