Approximation hardness of Shortest Common Superstring variants

Restricted Common Superstring and Restricted Common Supersequence

The shortest common superstring and the shortest common supersequence are two well studied problems having a wide range of applications. In this paper we consider both problems with resource constraints, denoted as the Restricted Common Superstring (shortly RCSstr) problem and the Restricted Common Supersequence (shortly RCSseq). In the RCSstr (RCSseq) problem we are given a set S of n strings,...

Improved Lower Bounds for the Shortest Superstring and Related Problems

We study the approximation hardness of the Shortest Superstring, the Maximal Compression and the Maximum Asymmetric Traveling Salesperson (MAX-ATSP) problem. We introduce a new reduction method that produces strongly restricted instances of the Shortest Superstring problem, in which the maximal orbit size is eight (with no character appearing more than eight times) and all given strings having ...

Improved Inapproximability Results for the Shortest Superstring and Related Problems

We develop a new method for proving explicit approximation lower bounds for the Shortest Superstring problem, the Maximum Compression problem, the Maximum Asymmetric TSP problem, the (1,2)–ATSP problem and the (1,2)–TSP problem improving on the best known approximation lower bounds for those problems.

Sequential and Parallel Algorithms for the Shortest Common Superstring Problem

We design sequential and parallel genetic algorithms, simulated annealing algorithms and improved greedy algorithms for the shortest common superstring problem(SCS), which is to find the shortest string that contains all strings from a given set of strings. The SCS problem is NP-complete [7]. It is even MAX SNP hard [2] i.e. no polynomial-time algorithm exists, that can approximate the optimum ...

Explicit Inapproximability Bounds for the Shortest Superstring Problem