# then try to solve from the next cell k+1, # fill the cell with value x only if x has not appeared on the same row or col or 3x3 box # try to fill each value from 1 to 9 in this cell # if this cell has been filled, go on to solve the next cell # return True to notify that we have found a solution # if we get pass the last cell, it means we have filled every cells with valid values. # k is the cell index, counting from left to right and top to bottom. # given the sudoku has been filled up to cell k-1, try to solve the sudoku from cell k # return False if value x has already been used in other cells on current row, or column, or 3x3 boxįor r in range(box_start_row, box_start_row + 3):įor c in range(box_start_col, box_start_col + 3):
HARD SUDOKU WITH SOLUTION CODE
The following sample code is written in Python. Note that in the above algorithm, every time we try to solve the board at cell k, we know that all cells from 0 to k-1 has already been filled with either the initial given puzzle value, or with a “test value” at a previous step.
Therefore, we can use the simplest algorithms to beat it within the allowed time frame. The function should return solution like this: ,Īlthough the testing puzzles to are going to be “hard”, the challenge only require us to return one solution. Our function should solve puzzles like this: puzzle = \ """return the solved puzzle as a 2d array of 9 x 9""" We have to write a function like this: def solve(puzzle): It might require some sort of brute force.įor Sudoku rules, see the Wikipedia article. The solution only need to give one valid solution in the case of the multiple solution sodoku. The Sudokus tested against your function will be “insane” and can have multiple solutions. The function will take one argument consisting of the 2D puzzle array, with the value 0 representing an unknown square. This kata is a harder version of Sudoku Solver made by a function that will solve a 9×9 Sudoku puzzle. It is recommended that you try to practice on your own first before going on to read the solution. Note that the solution in this blog can be used to pass both challenge 1 and 2, without any modification or optimization. This blog will focus on solving challenge 2 Hard Sudoku Solver, leaving challenge 3 Hard Sudoku Solver 1 for the next blog. However, Challenge 3 requires us to find all solutions, so it’s more challenging to beat the running time limit. The challenges that I will try to solve are listed below:Ĭhallenge 1 and challenge 2 only require us to find one solution, so the running time is not that critical. Part 1 will try to solve easier puzzles while Part 2 will try to solve harder ones. In this two-part blog series, I’m going to share my experience while solving the sudoku challenges on Codewars.
HARD SUDOKU WITH SOLUTION FULL
Bigger print than most newspapers 4 Sudoku Puzzles per page - Full of Fun and enjoy playing Wide inner margins so you can easily tear pages out Size of the book: 8.How fast is your sudoku solver algorithm? Can it beat the time limit on this Codewars challenge? If you get a timeout, welcome to my world! ?
HARD SUDOKU WITH SOLUTION PRO
Details about this Sudoku puzzle book Hard Volume 1: Lots of sudoku puzzles: 200 Sudokus Includes instructions, techniques and pro tips. Solving the Sudoku Puzzles is the best Brain Exercise. The book also helps in non-verbal skills. This 200 Hard Sudoku puzzle book for Adult & Kids offers a wide variety of puzzles which will create the fun in your life. If you love to resolve the Sudoku puzzles than this will be your best experience. The Sudoku Puzzles sharpen the memory, increase the concentration, and best remedy for depression. Take a break, relax, and do a little puzzling! The book contains 200 Hard Sudoku puzzles. 200 Hard Sudoku Puzzle to Improve Your Memory & Delay Brain Decline, with Solutions and Instructions.