sudoku | Sudoku solver using Dancing Links | Learning library
kandi X-RAY | sudoku Summary
kandi X-RAY | sudoku Summary
Sudoku can be reduced to a exact cover problem which is known to be NP-complete. The classification of NP-complete is only for a generalized nxn Sudoku and not a 9x9 Sudoku because it is a finite instance. The exact cover problem is a decision problem where the objective is to find a exact cover. Given a set S and another set where each element is a subset to S, is is possible to select a set of subsets such that every element in S exist in exactly one of the selected sets? This selection of sets is said to be a cover of the set S. Algorithm X (ALX) created by Donald Knuth can be used to find all solutions to a exact cover problem. Dancing Links (DLX) is the technique suggested by Knuth for implementing Algorithm X efficiently. This solver implements the DLX algorithm as described by Knuth but the reduction of a Sudoku to a exact cover problem is not truly a full reduction because its reduced directly to the links used in DLX. The full reduction would have been to first reduce the Sudoku to a binary matrix and then create the links used in DLX. The only reason for this is gain in performance but it is less flexible since this reduction can only be used with DLX.
Support
Quality
Security
License
Reuse
Top functions reviewed by kandi - BETA
- Solve a line by line
- Solve the grid
- Convert c
- Print grid solutions
- Performs a search
- Solve a single line
- Uncover all nodes in the tree
- Return the first column in the table
- Parse Sudoku line
- Print an error
- Search the given s
- Validate the Sudoku grid
- Create a grid from a Sudoku grid
- Validate the result
- Validates the Sudoku solution
- Format a grid
- Builds a grid from a list of Ks
sudoku Key Features
sudoku Examples and Code Snippets
Community Discussions
Trending Discussions on sudoku
QUESTION
ANSWER
Answered 2021-Jun-11 at 21:05Example for demonstration. It is not as difficult as in the picture in the question. But it will not be a problem for you to supplement it.
QUESTION
I need to be able to download a sudoku file with int values like this one:
partie1.txt {001 012 023 034 045 056 067 078 089 102 113 124 135 146 157 168 179 181 203 214 225 236 247 258 269 271 282 304 315 326 337 348 359 361 372 383 405 416 427 438 449 451 462 473 484 506 517 528 539 541 552 563 574 585 607 618 629 631 642 653 664 675 686 708 719 721 732 743 754 765 776 787 809 811 822 833 844 855 866 877 888}
and be able to use it in a sudoku game.
How do I download a file in string, convert it to ints, and put those values into a 2D array?
...ANSWER
Answered 2021-Jun-05 at 07:11import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Arrays;
public class Main {
static Integer[][] convertStringTo2DArray(String s) {
String[] sArray = s.split(" ");
Integer[][] intArray = new Integer[sArray.length][3];
for (int i = 0; i < sArray.length; i++) {
for (int j = 0; j < 3; j++) {
intArray[i][j] = Integer.parseInt(sArray[i].split("")[j]);
}
}
return intArray;
}
public static void main(String[] args) throws IOException {
File FichierALire1 = new File("C:\\Users\\amish\\Desktop\\partie.txt");
try (BufferedReader leBuffer1 = new BufferedReader(new FileReader(FichierALire1));) {
StringBuilder everything = new StringBuilder();
String line;
while ((line = leBuffer1.readLine()) != null) {
everything.append(line);
}
String partie = everything.toString();
partie = partie.trim();
System.out.println(Arrays.deepToString(Main.convertStringTo2DArray(partie)));
leBuffer1.close();
} catch (FileNotFoundException exception) {
System.out.println(" Fichier introuvable!");
}
}
}
QUESTION
I'm creating a sudoku solver desktop application with a GUI using Tkinter. The issue I'm having is when it comes to inputting the board. Here is the code I'm using:
...ANSWER
Answered 2021-May-28 at 20:22Consider this line of code:
QUESTION
I made a backtracking code which solves a sudoku and I want to display it on the screen using C libraries. I know that I can use GTK, but I think it is too complicated for my level.
How can I create an image with the solution displayed on a sudoku grid. It doesn't need to create the grid too, it is ok if I use an image with a grid as an input. So basically, I have a matrix (the sudoku solution) and I want to display it as an image.
I mention that I use VSC on a Virtual Machine with Mint.
...ANSWER
Answered 2021-May-27 at 18:15From my top comments ...
I assume you already have a 2D matrix that represents your board position.
You might consider using SDL2 instead of GTK as it's much simpler and can display directly to a window.
Or, you can create an image file and then use system to invoke a display program (e.g. ImageMagick's display command). It's pretty easy to output a .bmp file.
Or, you could create a .ppm format file--that's even simpler.
You could even output text graphics as a sudoku representation isn't too complex.
ImageMagick's convert can convert a format to any other format.
Thank you for your help! I still have a question. @CraigEstey, How do I convert my 2D matrix who looks like a sudoku into a matrix that can be displayed as a ppm or bmp. I assume that I need to have a matrix of pixels for that. – Ionut Becheru
Yes, you'll need a pixel matrix.
But, if you just create that yourself, you'll have to create a bunch of drawing primitives for drawing rectangles, drawing text fonts, adding colors, etc. In particular, drawing text into an image is complicated (we need a font definition).
So, once again, I suggest using a graphics package that does all that for you. And, again, I suggest SDL2.
In addition to the development package for SDL2, [on fedora, at least], you'll need to install the development package for SDL2_ttf. And, you'll need the font packages.
So, you'll need:
QUESTION
I'm trying to implement a backtracking algorithm to solve a sudoku, but for some reason it generates duplicate values in the same row/column, which isn't allowed.
The algorithm:
...ANSWER
Answered 2021-May-21 at 20:09The main issue is that you are only looking at the original grid to restrict values, whereas really you need to know about the trial values that you have put in your solution grid of Cells. So adjust your gen_possible_for to look at the Cells, not the original puzzle grid.
You also need to make sure that you clear Cell values as you backtrack past them, in that case, and have a way of backtracking past prefilled cells. And you need to hold the list of possible values for each cell (until you backtrack past it); if you .pop() values from this list then you don't also need to keep track of visit numbers.
QUESTION
This route is supposed to get a response from an external API, and return its body.
...ANSWER
Answered 2021-May-15 at 21:31I think res.json doesn't return a promise, so i guess it just silently throws an error. Besides, what should .then('Sudoku generated') really do?
Try removing that part and move the catch out too
QUESTION
Learning this tutorial at OpenCV of Adaptive-Thresholding, exact code copied
...ANSWER
Answered 2021-May-12 at 23:41That's not the EXACT code. The exact code reads a grayscale PNG. You have a color JPG. That's the difference. adaptive threshhold requires a grayscale image. So, add:
QUESTION
I am writing a sudoku Puzzle in Haskell and I have a [[Maybe Int]] where I need to check which of the [Maybe Int] contains the least Nothing elements. In other words, in the following code I should return 1, which is the position of the list with only two Nothing:
...ANSWER
Answered 2021-May-11 at 05:08So you want to find the (index-of) the minimum element according to some metric – in your case number of Nothing elements, but clearly this is a special case of a more general concept: you have some function a -> Int to be used on the elements of an [a] list. In other words, you need a helper with a signature like either
QUESTION
Im trying to create a function that given a sudoku board, row, column and value, it iterates through the subgrid to which the row and column belongs to and checks if the value is in that subgrid. I have already made the function that identifies to which subgrid the row and column belongs. Im stuck with the function that checks if the value is in that subgrid. Eg:
...ANSWER
Answered 2021-May-09 at 09:30[too long for a comment]
Understanding what you have so far would be easier with a bit more of your code and data structures. Commonly (but definitely not always), a sudoku board is set up as list of rows, each of which is a list of numbers, zeroes representing blanks:
QUESTION
Im trying to get familiar with constraints in Prolog and I'm having trouble understanding the program below:
...ANSWER
Answered 2021-May-06 at 22:48What happens is:
sudoku/1imposes constraints on a 9x9 matrix of elements- with the help of
blocks/2
- with the help of
problem/2lists a particular problem
And we can then put both together:
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install sudoku
Support
Reuse Trending Solutions
Find, review, and download reusable Libraries, Code Snippets, Cloud APIs from over 650 million Knowledge Items
Find more librariesStay Updated
Subscribe to our newsletter for trending solutions and developer bootcamps
Share this Page
