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## Sudoku Puzzle Creation

When your spiffy Computerized, Programmatic Sudoku Puzzle Generator is not available, consider the low-technology, self-involving, self-sufficient random number generator and cell locator tools. You need at least 17 starting numbers and symmetry is required only for the obsessive compulsive (or Virgo people). Don’t start with too many numbers, though, unless creating unsolvable puzzles is your goal.

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## Shogi Sudoku

I have been a long time Shogi (Japanese Chess) player. The problem is too few worthy opponents. This may be due to the fact that playing Shogi for any length of time fosters frequent sacrifices, which totally ruins you for regular chess.

Shogi is played on a 9 x 9 square board and your pieces are pointing away from you. Your opponent’s pieces are pointing toward you. One major feature that distinguishes Shogi from Western Chess is that pieces that you capture become yours to play again anywhere unoccupied on the board. (pawns only drop onto your non-pawn lanes.) As a result, there are no draws in Shogi.

It took me about a month to recognize the Japanese characters reliably, without referring to the names and pictures. Once you study the characters, they are quite dissimilar from each other and have unique identification areas. While western chess emulates middle-ages warfare, Shogi is more a metaphor for aerial warfare a la World War 1 (and perhaps 2).

Other resources for this game include shogi.net, shogi.com, the Ricoh Shogi Club and the Computer Shogi Association which tracks the World Computer Shogi Championships.

For the last few weeks, I’ve been swamped with extra curricular activities which has constrained my writing here. I hope to resume in May.

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## Twin Sudoku

Without instructions, I’m showing (by example) how to do these two interrelated and yet independent Sudoku puzzles. Thanks to Henry Kwok for the idea, although his example maps two sets of digits, which may be more difficult (confusing).

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## Linear Sudoku

The idea for using a string of 81 single digits [the solution] or 81 characters including the blank character [the unsolved puzzle] probably originated on Usenet due to the text based messaging used there. I’ve always been fascinated with Mobius Strips and Klein Bottles (the 3-D analogue). A very enjoyable, math oriented book first published in 1958, Edited by Clifton Fadiman, called Fantasia Mathematica conjectures about the possibilities raised by these strange objects, among other science fiction topics.