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04 March 2007 @ 06:43 pm
Courtesy of jdyer's excellent posts on worldpuzzle, I went through the Japanese Number Place Championship today. With solvable examples as well as the real problems it is a large batch of puzzles with some really interesting variants appearing. Highly recommended. I did finish all the puzzles before the 3 hour time limit but I really messed up the last type which was quite challenging until I converted it in my mind to a 0-9 sudoku with nine double-valued cells.
THrpipuzzleguy on March 4th, 2007 11:57 pm (UTC)
I can't even figure out the instructions for some of these.
motrismotris on March 4th, 2007 11:59 pm (UTC)
I hate spoiling them for people (figuring them out was half the fun - like the picture in 23 suggesting a chess like number restriction), but tell me the numbers you don't get and I can give you the right rules. I have all but a subtle point of 4 (but do have the main point of 4).
motrismotris on March 5th, 2007 02:44 am (UTC)
Spoilers below, but here are my "instructions" for the puzzles on the Japanese test.

There's no PDF in english but I can give you the instructions for all the puzzles as I know them.

1 - 4x4x4 sudoku - all 4 puzzles are valid sudoku with numbers 1-4 and no number repeats in the same position in any of the puzzles (as if it were a 4x4x4 cube of them)

2 - standard sudoku
3 - jigsaw sudoku

4 - I'll call it a "mine" sudoku - fill each box/row/column with the digits 1 through 4 and two mines. The boxed squares must contain a number (1-4), and that number must be the number of mines immediately adjacent (vertically or horizontally) to that square. There is one other rule I don't know to resolve uniqueness, but that rule will get you to one of 2 solutions with either an interchangable pair of 13s in the example or 14s in the puzzle.

5 - cubic as in WSC 1

6 - heptoku style - 1 to 7 in each of the three directions

7 - poorly presented, but a mechanical sudoku. The 7 pieces you use are on the last page of the pdf and can be rotated but don't need to be flipped like in the WSC 1.

8 - pips as in wsc

9 - toroidal jigsaw

10 - consecutive sudoku (all consecutive digits that are adjacent have a special marking between them)

11 - "repeated region" sudoku - solve both sudoku so that each is valid, and in each box marked with a katakana character, the corresponding box in the other puzzle uses the exact same arrangement of numbers.

12 - diagonal pair sudoku - Each "X" marks a unique sum that is formed by the two digits connected on each diagonal of the X. In other words A+B = C+D must be true for each diagonal formed on an X.

13 - nonconsecutive sudoku - consecutive digits never touch.

14 - "Arrow" Sudoku - the numbers in the circles are equal to the sums of the digits of all cells touched by the arrows. Digits can repeat in a sum (unlike the typical sum/product sudoku rule).

15 - Not sure of the japanese name. Each row/column must have the numbers 1 through 7 once, and in each shaded box with "n" cells, there will be a sequence of "n" consecutive numbers. So, as an example, if there are 5 cells and one of them is a 2, then the cells contain either 1 through 5 or 2 through 6. The numbers needn't be entered in order, just form a consecutive set when considered as a whole.

16 - outside sudoku as in WSC (digits mark the row/column where in the closest box those numbers occur)

17 - I'll call it an "Easy As Sudoku". Fill each row/column/box with the numbers 1 through 5 (and 4 empty squares); the numbers on the outside indicate the first number encountered in that direction in the grid.

18 - sum sudoku
19 - product sudoku
20 - digital sudoku
21 - domino sudoku - each shaded region (white or grey box) is a 6 cell region that takes the numbers 1 through 6. The smaller areas (2 cell or 1 cell) indicate dominos and you must place each domino in the set exactly once.

22 - frame sudoku as in WSC (givens are the sums of the first three digits in that row/column)

23 - Knight move sudoku - numbers cannot appear a knights move away from themselves.

24 - Unknown name - There are 2 groupings of numbers into sets of three. In the white groupings, 1-3, 4-6, and 7-9 are the three sets, and whenever any members of these sets touch (1 next to 2 or 3), a white dot marks the connection. There are also black groupings (147), (258), (369) and whenever any members of a black grouping touch, a black dot marks the connection.

25 - Pandigital (as in WSC)

26 - (almost a 0-9 sudoku) - Each row, column, and box will contain 9 of the 10 digits from 0-9. The numbers on the outside of the grid indicate the number that does not appear in each row. I found this one very hard initially, but then realized that it can be turned into a 0/9 sudoku (by adding in the "extra" digit that was removed. This was the hardest for me on the whole test.
tombodamatombodama on March 5th, 2007 02:48 am (UTC)
Thanks much! Looks like fun.
motrismotris on March 5th, 2007 02:50 am (UTC)
yep. seems like your request got caught up with my writing these instructions (sent to a US sudoku teammate) but good luck playing around with some of these.
(Anonymous) on March 5th, 2007 03:37 pm (UTC)
The missing rule for 4 is :
a number in non-box square must be different from the number of mines immediately adjacent to that cell.

For other puzzles, you understand the rule quite well.
I'm a Japanese, got third place at this competition.

T. Arimatsu
Adam R. Wood: butasanzotmeister on March 5th, 2007 05:42 pm (UTC)
So THAT was the rule I was stuck on! You'd think I of all people would have gotten that rule... - ZM
Adam R. Wood: butasanzotmeister on March 5th, 2007 05:47 pm (UTC)
Oh, and congratulations on your performance! - ZM
lunchboylunchboy on March 5th, 2007 07:37 pm (UTC)
Aha! I was just trying to figure that out. Makes perfect sense now that you say it.
jdyer on March 6th, 2007 01:41 pm (UTC)
Thanks, a couple of these were mystifying me.

I presume the Mechanical Sudoku has no flipping because the players may not necessarily have transparency paper to print on for flipping purposes.

And thank you for the kind words.
tombodamatombodama on March 5th, 2007 02:45 am (UTC)
I took Japanese a long time ago in school, but I'm not that enthusiastic about poring through my Kanji dictionary. (Katakana is still useful though- e.g. 23 reads "Knight Step")

I was wondering about 4- seems clear except for the function of the small squares.

I'd also be curious about the rules for 7, 12, 13, 14. I think I understand 7 (the extra pieces are on p. 27?).