Snake-In-The-Box Codes for Dimension 7

Krys J. Kochut 1
1 Department of Computer Science University of Georgia Athens, Georgia 30602-7404, USA

Abstract

In the \(n\)-dimensional hypercube, an \(n\)-snake is a simple path with no chords, while an \(n\)-coil is a simple cycle without chords. There has been much interest in determining the length of a maximum \(n\)-snake and a maximum \(n\)-coil. Only upper and lower bounds for these maximum lengths are known for arbitrary \(n\). Computationally, the problem of finding maximum \(n\)-snakes and \(n\)-coils suffers from combinatorial explosion, in that the size of the solution space which must be searched grows very rapidly as \(n\) increases. Previously, the maximum lengths of \(n\)-snakes and \(n\)-coils have been established only for \(n \leq 7\)and \(n \leq 6\), respectively. In this paper, we report on a coil searching computer program which established that \(48\) is the maximum length of a coil in the hypercube of dimension \(7\).