New Puzzle based on Rogaining


Two Canterbury Uni academics have invented a puzzle which they hope will rival Sudoku. Rogo takes its name from "rogaining", and the challenge is to plot a path round numbers on a crossword-like grid, gathering the highest possible score. Players are told the maximum number of moves allowed and the perfect score.

Nicola Petty (who took up rogaining last year) and Shane Dye are senior lecturers in the Dept of Management, and see similarities between rogaining and their specialty of operations research, which uses mathematics to understand and improve processes in business. While chasing controls in the countryside, she wiondered how teh physical challenge could be translated into a board game.

They tested the game with other staff, before Dye took it home for his kids to have a go. They found that using counters to plot where they had been was awkward, and that it worked better with a pen. Dye says that a class of 12-year-olds was enthusiastic, and thought the game was at least as good as Sudoku. That's when they started to think "we're onto something here."

Petty explains that in operations research rogaining (and the puzzle) is called a "subset selection prize-collecting travelling salesman problem". It is very difficult to solve mathematically, but Shane came up with a very neat way of doing it in a reasonable amount of computer time. This lets them create puzzles, find the best possible solution, and check that there are enough red herrings to make the puzzles interesting to solve.

Of course you're not allowed to use a computer in rogaining. But it may be that some practice with Logo could improve your route-planning abilities. Rogo books are on sale at the Chch arts centre market, and The Press (Chch daily paper) has begun running a weekly Rogo puzzle. The pair are now working on an iPhone application, and talking to puzzle-book publishers.

This material is based closely on an article in "Canterbury", the magazine for alumni and friends of the University of Canterbury, Vol 7 No 1, Winter 2010. Find out more at the Rogo website.


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