On the Computational Complexity of Integer Programming Problems

Recently much effort has been devoted to determining the computational complexity for a variety of integer programming problems. In this paper a general integer programming problem is shown to be NP-complete; the proof given for this result uses only elementary linear algebra. Complexity results are also summarized for several particularizations of this general problem, including knapsack problems, problems which relax integrality or non-negativity restrictions and integral optimization problems with a fixed number of variables.