We’ll use these functions for debugging as we go forward. We see that, at the start, all the non-filled cells have all the digits as possible values. > putStrLn $ showGridWithPossibilities grid 1 4 2 5 4 7 8 3 1 9 3 4 2 5 1 8 6 We can write a few functions to clean it up: The output is a bit unreadable but correct. > Just grid = readGrid ".1.4.2.5.4.7.8.3.1.9.3.4.2.5.1.8.6." > mapM_ print grid ,Possible ,Possible ,Possible ,Possible ,Possible ,Possible ,Fixed 1,Possible ] ,Possible ,Possible ,Possible ,Possible ,Possible ,Possible ,Possible ] ,Fixed 2,Possible ,Possible ,Possible ,Possible ,Possible ,Possible ,Possible ] ,Possible ,Possible ,Possible ,Fixed 5,Possible ,Fixed 4,Possible ,Fixed 7] ,Possible ,Fixed 8,Possible ,Possible ,Possible ,Fixed 3,Possible ,Possible ] ,Possible ,Fixed 1,Possible ,Fixed 9,Possible ,Possible ,Possible ,Possible ] ,Possible ,Fixed 4,Possible ,Possible ,Fixed 2,Possible ,Possible ] ,Fixed 5,Possible ,Fixed 1,Possible ,Possible ,Possible ,Possible ,Possible ] ,Possible ,Possible ,Fixed 8,Possible ,Fixed 6,Possible ,Possible ,Possible ] For example, a grid showing the possibilities of all non-filled cells for the sample puzzle above: Each cell contains either a single digit or has a set of possible digits.Given these constraints, we can devise a simple algorithm to solve Sudoku: For example, if a cell contains 1 then no other cell in that cell’s row, column or sub-grid can contain 1. Enter the numbers of the puzzle you want to solve in the grid. Digits in the pre-filled cells impose constraints on the rows, columns, and sub-grids they are part of. Each of the nine 3x3 sub-grids must have all the digits, from 1 to 9.Įach cell in the grid is member of one row, one column and one sub-grid (called block in general).Each of the nine columns must have all the digits, from 1 to 9.Each of the nine rows must have all the digits, from 1 to 9.We are given a partially filled grid which we have to fill completely such that each of the following constraints are satisfied: Solving Sudoku is a constraint satisfaction problem. Fast Sudoku Solver in Haskell #3: Picking the Right Data Structures.Fast Sudoku Solver in Haskell #2: A 200x Faster Solution.Fast Sudoku Solver in Haskell #1: A Simple Solution.This is the first post in a series of posts: We’ll focus on both implementing the solution and making it efficient, step-by-step, starting with a slow but simple solution in this post 1. The aim of this series of posts is to write a fast Sudoku solver in Haskell. ![]() ![]() It is a good choice to solve Sudoku given the problem’s combinatorial nature. Haskell is a purely functional programming language. Some of the cells of the grid come pre-filled and the player has to fill the rest. It consists of a 9x9 grid which is to be filled with digits from 1 to 9. Tags: programming puzzles haskell nilenso.Fast Sudoku Solver in Haskell #1: A Simple Solution | About Posts Notes μBlog Projects Photos Readings Activities Now Fast Sudoku Solver in Haskell #1: A Simple Solution
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |