activity
20122025
most citedParameterized Approximation Algorithms for -Center Clustering and Variants

2 citations · 5 across the 16 of their papers we have counts for

collaborators

24 papers

cs.LG2025

Budget-constrained Active Learning to Effectively De-censor Survival Data

Ali Parsaee, Bei Jiang, Zachary Friggstad +1

Standard supervised learners attempt to learn a model from a labeled dataset. Given a small set of labeled instances, and a pool of unlabeled instances, a budgeted learner can use…

cs.DS2025

Approximating Multiple-Depot Capacitated Vehicle Routing via LP Rounding

Zachary Friggstad, Tobias Mömke

In Capacitated Vehicle Routing with Multiple Depots (CVRP-MD) we are given a set of client locations and a set of depots located in a metric space with costs betwe…

cs.DS2024★ 1 cited

Approximation Algorithms for Clustering with Minimum Sum of Radii, Diameters, and Squared Radii

Zachary Friggstad, Mahya Jamshidian

In this paper, we present an improved approximation algorithm for three related problems. In the Minimum Sum of Radii clustering problem (MSR), we aim to select balls in a metr…

cs.DS2024

Approximate Minimum Sum Colorings and Maximum -Colorable Subgraphs of Chordal Graphs

Ian DeHaan, Zachary Friggstad

We give a -approximation for the minimum sum coloring problem on chordal graphs, improving over the previous 3.591-approximation by Gandhi et al. [2005]. To do so, we al…

cs.DS2024

A QPTAS for Facility Location on Unit Disk graphs

Zachary Friggstad, Mohsen Rezapour, Mohammad R. Salavatipour +1

We study the classic \textsc{(Uncapacitated) Facility Location} problem on Unit Disk Graphs (UDGs). For a given point set in the plane, the unit disk graph UDG(P) on has ve…

cs.DS2024

Approximating Traveling Salesman Problems Using a Bridge Lemma

Martin Böhm, Zachary Friggstad, Tobias Mömke +1

We give improved approximations for two metric Traveling Salesman Problem (TSP) variants. In Ordered TSP (OTSP) we are given a linear ordering on a subset of nodes $o_1, \ldots, o_…