The minimum size of critical sets in latin squares
โ Scribed by Chin-Mei Fu; Hung-Lin Fu; C.A. Rodger
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 224 KB
- Volume
- 62
- Category
- Article
- ISSN
- 0378-3758
No coin nor oath required. For personal study only.
โฆ Synopsis
A critical set C of order n is a partial latin square of order n which is uniquely completable to a latin square, and omitting any entry of the partial latin square destroys this property. The size s(C) of a critical set C is the number of filled cells in the partial latin square. The I size of a minimum critical set of order n is s(n). It is likely that s(n) is approximately ~n-, though to date the best-known lower bound is that s(n)>~n + 1. In this paper, we obtain some conditions on C which force s(C)>~ L(n-l)/2J 2. For n > 20, this is used to show that in general s(n)>~ [(7n -3)/6j, thus improving the best-known result.
๐ SIMILAR VOLUMES
## Abstract A critical set is a partial latin square that has a unique completion to a latin square, and is minimal with respect to this property. Let __scs__(__n__) denote the smallest possible size of a critical set in a latin square of order __n__. We show that for all __n__, $scs(n)\geq n\lfloo
## Abstract Suppose that __L__ is a latin square of order __m__ and __P__โโโ__L__ is a partial latin square. If __L__ is the only latin square of order __m__ which contains __P__, and no proper subset of __P__ has this property, then __P__ is a __critical set__ of __L__. The critical set spectrum p
## Abstract In this paper, we study the problem of constructing sets of __s__ latin squares of order __m__ such that the average number of different ordered pairs obtained by superimposing two of the __s__ squares in the set is as large as possible. We solve this problem (for all __s__) when __m__
The maximum size of a jump-critical ordered set with jump-number m is at most (m + l)! AMS (MOS) subject classifications (1980). Primary 06AlO; secondary 68C25.