sudoku

sudoku, a data directory which contains examples of Sudoku puzzles. A 9x9 grid of 3x3 boxes and 81 cells is presented. In a completed Sudoku, the digits 1 through 9 are placed in the 81 cells, in such a way that each row, column and box contains each digit exactly once. A Sudoku puzzle is a partially completed Sudoku in which the user must figure out how to complete the pattern. In an uncompleted puzzle, each missing digit is indicated by a '0' digit.

The first 16 example puzzles were collected by Cleve Moler, and presented as part of his text "EXM: Experiments with MATLAB".

Licensing:

The information on this web page is distributed under the MIT license.

Related Programs and Data:

exm, a MATLAB code which contains scripts and data discussed in the electronic textbook "Experiments with Matlab", by Cleve Moler, including easter, Fast Fourier Transforms, Fibonacci numbers, the fractal fern, the game of Life, magic matrices, the Mandelbrot set, Morse code, Music, Ordinary Differential Equations, the page rank algorithm, planetary orbits, predator prey equations, the shallow water equations, Sudoku puzzles.

sudoku, a MATLAB code which handles Sudoku puzzles;

Reference:

• Cleve Moler,
  Experiments with MATLAB,
  ebook: https://www.mathworks.com/moler/exm/index.html
• https://www.mathworks.com/moler/exm/chapters.html , the chapters of the book.
• https://www.mathworks.com/matlabcentral/fileexchange/37977-experiments-with-matlab the accompanying MATLAB codes, images, and other data files.

Source code:

1. puzzle_01.txt, Incorporates magic square.
2. puzzle_02.txt, Easy, no backtracking required.
3. puzzle_03.txt, Slightly difficult, only a few backtracking steps, not unique.
4. puzzle_04.txt, Four-fold rotational symmetry. Not too difficult.
5. puzzle_05.txt, Moderately difficult, a few hundred backtracing steps.
6. puzzle_06.txt, An airline magazine says this is difficult. Is it?
7. puzzle_07.txt, Solution is not unique. Herzberg and Murty, Notices AMS, v.54, n.6, June 2007.
8. puzzle_08.txt, Difficult. Only 17 nonzero initial entries. Herzberg and Murty, Notices AMS, v.54, n.6, June 2007.
9. puzzle_09.txt, Good example of backtracking. Michael Mephapm, "Diabolical"
10. puzzle_10.txt, Beware. Very Challenging." Will Shortz, puzzle 301.
11. puzzle_11.txt, "Beware. Very Challenging." Will Shortz, puzzle 400.
12. puzzle_12.txt, Structural symmetry and not too difficult. American Math Monthly.
13. puzzle_13.txt, Nice spiral pattern, but there are 346 solutions. Salim Jaliwala, "Scratch n' Play Sudoku", volume 1, page 80.
14. puzzle_14.txt, Structural symmetry. Gordon Royle, University of Western Australia
15. puzzle_15.txt, Very close to matrix symmetry, and very difficult. Gordon Royle, University of Western Australia.
16. puzzle_16.txt, Structural symmetry and only 17 nonzero initial entries. Gordon Royle, University of Western Australia.

1. solution_01.txt
2. solution_02.txt
3. solution_03.txt
4. solution_04.txt
5. solution_05.txt
6. solution_06.txt
7. solution_07.txt
8. solution_08.txt
9. solution_09.txt
10. solution_10.txt
11. solution_11.txt
12. solution_12.txt
13. solution_13.txt
14. solution_14.txt
15. solution_15.txt
16. solution_16.txt