An Improved Approximation Algorithm for Multiway Cut

Given an undirected graph with edge costs and a subset of k nodes called terminals, a multiway cut is a subset of edges whose removal disconnects each terminal from the rest. Multiway Cut is the problem of finding a multiway cut of minimum cost. Previously, a very simple combinatorial algorithm due to Dahlhaus, Johnson, Papadimitriou, Seymour, and Yannakakis gave a performance guarantee of 2 1 − 1 k . In this paper, we present a new linear programming relaxation for Multiway Cut and a new approximation algorithm based on it. The algorithm breaks the threshold of 2 for approximating Multiway Cut, achieving a

• Type: Conference
• Year: 1998
• Where: STOC
• Authors: Gruia Calinescu, Howard J. Karloff, Yuval Rabani
• Keywords: Algorithms, Multiway Cut, Nodes Called Terminals, Simple Combinatorial Algorithm, STOC 1998