As you probably know, my online pseudonym is Puzzle Doctor (occasionally branching out to THE Puzzle Doctor depending on how self-important I’m feeling 🙂 ) but only part of the “Puzzle” bit relates to my reading preferences. It also relates to actual puzzles, which I’m also a fan of.
Last month I was very proud of two things – being able to help out at the World Sudoku Championships and competing for the United Kingdom in the World Puzzle Championship. I mentioned it in the Puzzly post and there were a couple of requests for more information. So here we go…
First of all, what are these Championships? Well, they are both run by the World Puzzle Federation – each country that is a member of the WPF can enter a team of four competitors. A different country hosts each year and arranges the specific format of the competition, with most of the puzzles set by people from that country. The competitors compete both as a team and also as individuals across two days – the team score consists of the total of the individual scores and the scores in some team rounds, designed for all four solvers to cooperate in finding the solution.
What sort of puzzles are involved here? Well, the sudoku competition is more than just normal 9 x 9 grids. The majority of puzzles will contain an extra rule – for example, no touching squares can contain consecutive numbers; no cells linked by a knight’s move can contain the same number, etc. If you would like to see the full range of puzzles, then follow this link to the UK Puzzle Association website – each puzzle type contains an example with the solution provided. I’m afraid for copyright purposes, I can’t link to the competition puzzles themselves, but this is the next best thing.
That’s the WSC, but what sort of puzzles are in the WPC? A much wider range that would take too long to itemise. The main condition on a puzzle being valid is that it is language neutral and does not depend on general knowledge. You may have seen examples in newspapers – Kakuro and Futoshiki make appearances in the UK press for example – but the variety extends far beyond that. Let’s give a couple of examples that you probably won’t have seen, copyright me (the puzzle itself, not the type).
Japanese Sums – in the grid, either shade the cells or place a digit from 1 to 6. The digits cannot repeat in a row or column, but all digits do not need to appear in each row or column. The clues for each row and column represent the sum of each string of digits (or single digit) in that row/column, which must be separated by at least one shaded cell.
Tetronimos – place the complete set of tetronimos (i.e. the seven Tetris pieces) in the grid so that the number by a row or column indicates the number of empty cells before the first used tetronimo is encountered. An unclued row or column means that there can be any number of empty cells, including none. The tetronimos cannot touch each other, not even diagonally.
This is only scratching the surface. Again, to get a feel for the entire range of puzzles that the solver is expected to deal with, this link will take you to the instruction booklet.
Well, I think I’ve said enough about the format. Come back tomorrow, and I’ll tell you something about what it’s like to compete in the tournament, and following that, I’ll direct you to some places to get loads of puzzles for free (mostly). And if you’re very good, I’ll post the solutions to these puzzles.