INGAR'S SUDOKU SOLVER I'm not a fervent sudoku solver but I always wanted to try implementing a program to solve the puzzles faster than I can. This is my first attempt. This program uses the Qt library for its user interface, you will need to have it installed to run the program. BUILDING INSTRUCTIONS Basic building instructions autoreconf -i mkdir build cd build ../configure make The binary will be called 'sudoku' and be located in the 'src' directory. You can run it from within the build directory: src/sudoku USAGE Running the program will show the main window, which consists of a basic sudoku grid (9x9) and a number of buttons. The LOAD button allows you to load a previously loaded game. The SAVE button allows you to save the current sudoku puzzle to a file, like wise, the LOAD button allwos you to load a previously saved sudoko. The CLEAR button will clear all values. The STEP button will solve a single cell, but only applies the sudoko rules, it will not "guess". The SOLVE button will try to solve the puzzle without "guessing". The SEARCH button will try to solve the puzzle and SAVE GAME FILE FORMAT The file format is extremely simple: the files can be opened and edited with a text editor. Note that empty (unsolved) positions are saved as well. Value 0 indicates an empty cell. Example: 0 0 0 8 0 2 9 0 0 0 0 0 9 0 7 3 6 0 4 0 9 0 0 0 0 0 7 0 8 0 0 0 5 0 4 6 1 3 0 0 7 8 0 0 0 0 0 0 2 0 0 0 7 0 3 4 6 1 2 0 7 0 0 0 1 0 0 0 0 6 0 2 0 5 0 0 8 0 0 0 0 While the file format is optimized for readability, the program will actually ignore extra whitespace while loading a file. This allows you to load games from a simple file with numbers. ALGORITHM The constraint solver will try to find a solution by applying two sets of sudoko constraints: the sudoku elimination rules, where every number from 1 to 9 can only appear once in every row, column and subgrid, and the sudoko inclusion rules, where every number has to appear exactly once in every row, column and subgrid, The search solver will apply constraints until there no more cells left with just one possibility. From there, it will pick a random empty cell and fill it with one of the remaining possibilities. From there it recurses into the next iteration. COPYRIGHT This sudoku solver was written by Stijn "Ingar" Buys and is available under the terms and conditions of the GNU Public License (GPL). Copyright (c) 2012-2013 ingar@telenet.be htpt://ingar.satgnu.net