KEMPE REVISITED

Citation
J. Hutchinson et S. Wagon, KEMPE REVISITED, The American mathematical monthly, 105(2), 1998, pp. 170-174
Citations number
9
Categorie Soggetti
Mathematics,Mathematics
ISSN journal
00029890
Volume
105
Issue
2
Year of publication
1998
Pages
170 - 174
Database
ISI
SICI code
0002-9890(1998)105:2<170:>2.0.ZU;2-K
Abstract
A practical way of colouring any map is this. Number the districts in succession, always numbering a district which has less than six bounda ries, not including those boundaries which have a district already num bered on the other side of them. When the whole map is numbered, begin ning sith the highest number, letter the districts in succession with four letters, a, b, c, d, rearranging the letters whenever a district has four round it. so that it may have only three, leaving one to lett er the district with. When thr whole map is lettered, colour the distr icts, using different colors for districts lettered differently.