% we subtract 0.5 to center the clue in the box. There are many approaches to solving Sudoku puzzles manually, as well as many. % boxes, j is the horizontal distance, 10-i is the vertical distance, and This example shows how to solve a Sudoku puzzle using binary integer programming. % the top, j is the column, and k is the clue. % The rows of B are of the form (i,j,k) where i is the row counting from Rectangle('Position','LineWidth',1) % minor vertical lines ![]() Rectangle('Position','LineWidth',1) % minor horizontal lines Rectangle('Position','LineWidth',2) % heavy horizontal lines Rectangle('Position','LineWidth',2) % heavy vertical lines Rectangle('Position','LineWidth',3,'Clipping','off') % outside border In other words, for every i and j,įigure hold on axis off axis equal % prepare to draw What properties does x have? First, each square in the 2-D grid (i,j) has exactly one value, so there is exactly one nonzero element among the 3-D array entries x ( i, j, 1 ). Suppose a solution x is represented in a 9-by-9-by-9 binary array. Express the Rules for Sudoku as Constraints However, for tie breaking in the internals of the integer programming solver, giving increased solution speed, use a nonconstant objective function. The problem is really just to find a feasible solution, meaning one that satisfies all the constraints. The objective function is not needed here, and might as well be a constant term 0. Instead, remain patient and think about the puzzle in front of you logically. That means you never have to guess when solving a Sudoku. Our last Sudoku tip is simple: Remember that Sudoku is a puzzle of logical deduction that uses the process of elimination to arrive at an unique solution. This formulation is precisely suited for binary integer programming. 10) Don’t guess use the process of elimination. The ninth layer has a 1 wherever the solution or clue has a 9. The second layer has a 1 wherever the solution or clue has a 2. The top grid, a square layer of the array, has a 1 wherever the solution or clue has a 1. ![]() Think of the cubic array as being 9 square grids stacked on top of each other, where each layer corresponds to an integer from 1 through 9. The second is to consider the different ways that a sum can be created. The key idea is to transform a puzzle from a square 9-by-9 grid to a cubic 9-by-9-by-9 array of binary values (0 or 1). The first is to use the strategies for solving regular sudoku puzzles. Just express the rules of Sudoku, express the clues as constraints on the solution, and then MATLAB produces the solution. This approach is particularly simple because you do not give a solution algorithm. This example shows a straightforward approach using binary integer programming. There are many approaches to solving Sudoku puzzles manually, as well as many programmatic approaches. This puzzle, and an alternative MATLAB® solution technique, was featured in Cleve's Corner in 2009.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |