Koen Ligthart

collaborators

3 papers

math.OC2026

Value Functions of Separable Convex Integer Programs are Periodically Convex

Koen Ligthart

We consider the periodic behavior of the value functions $b \mapsto min {f (x) ∣ A x = b, x \in Z_{\geq 0}^{n}}$ of integer programs. We show that there exists a positive inte…

cs.CC2026

Solving 4-Block Integer Linear Programs Faster Using Affine Decompositions of the Right-Hand Sides

Alexandra Lassota, Koen Ligthart

We present a new and faster algorithm for the 4-block integer linear programming problem, overcoming the long-standing runtime barrier faced by previous algorithms that rely on Gra…

cs.CC2025

Parameterized Algorithms for Matching Integer Programs with Additional Rows and Columns

Alexandra Lassota, Koen Ligthart

We study integer linear programs (ILP) of the form $min {c^{⊤} x ∣ A x = b, l \leq x \leq u, x \in Z^{n}}$ and analyze their parameterized complexity with respect to their dist…