A Class of Hard Small 0—1 Programs
Gérard Cornuéjols, and Milind Dawande
In Integer Programming and Combinatorial Optimization, Jan 1998
In this paper, we consider a class of 0–1 programs which, although innocent looking, is a challenge for existing solution methods. Solving even small instances from this class is extremely difficult for conventional branch-and-bound or branch-and-cut algorithms. We also experimented with basis reduction algorithms and with dynamic pro- gramming without much success. The paper then examines the perfor- mance of two other methods: a group relaxation for 0,1 programs, and a sorting-based procedure following an idea of Wolsey. Although the re- sults with these two methods are somewhat better than with the other four when it comes to checking feasibility, we offer this class of small 0,1 programs as a challenge to the research community. As of yet, instances from this class with as few as seven constraints and sixty 0–1 variables are unsolved.