The Weighted Integrity Problem is Polynomial for Interval Graphs

Sibabrata Ray1, Rajgopal Kannan2, Danyang Zhang3, Hong Jiang4
1Assistant Professor Dept. of Computer Science University of Alabama Tuscaloosa, AL 35487 USA
2Assistant Professor Dept. of Computer Science Louisiana State University Baton Rouge, LA 70803 USA
3Assistant Professor Communications Technology York College City University of New York Jamaica, NY 11451 USA
4Professor Computer Science and Engineering University of Nebraska—Lincoln Lincoln, NE 68588 USA

Abstract

Network reliability is an important issue in the area of distributed computing. Most of the early work in this area takes a probabilistic approach to the problem. However, sometimes it is important to incorporate subjective reliability estimates into the measure. To serve this goal, we propose the use of the weighted integrity, a measure of graph vulnerability. The weighted integrity problem is known to be NP-complete for most of the common network topologies including tree, mesh, hypercube, etc. It is known to be NP-complete even for most perfect graphs, including comparability graphs and chordal graphs. However, the computational complexity of the problem is not known for one class of perfect graphs, namely, co-comparability graphs. In this paper, we give a polynomial-time algorithm to compute the weighted integrity of interval graphs, a subclass of co-comparability graphs.