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# Sudoku Project in VS 2010

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16 Dec 2013CPOL2 min read 49.1K   2.5K   26   11
Sudoku game solver with a "SudokuControl"

## Introduction

This application tries to solve any Sudoku game. It applies all basic Sudoku logic to discover missing numbers:

1. Test of possible numbers in a cell by scanning all possibilities in that cell's row, column and square.
2. For each row, column and square, scan all numbers (from 1 to 9) to fit a number in its cell (for example: In the third row, number 5 can only be in the second cell because none of the other cells support it.)
3. Finally, if no searches of the previous types are found, trial and error starting in those cells that have least number of possibilities.

I made a YouTube playlist of the entire project. I was recording and writing the code at the same time.

## Background

Almost twelve (about 2000) years ago, I encountered the Sudoku game and it was love at first sight. I was studying Math in Faculdade de Ciências da Universidade do Porto (Portugal), and immediately I made an application to solve it (I programmed in Visual Basic 6 since I was 17). That application solved it with no problem. Now in 2013, for the first time, I'm unemployed since my degree (Portuguese economy sucks) and I decided to make a "remake" of that application because I've seen some bad Sudoku applications (by design). Because I've been teaching C#, SQL, and Math these last years, I think I can make a good app...

## Using the Code

The app consists of:

• A set of classes representing the Sudoku Game and structure
• A control named `SudokuControl` to present the game.

The classes that I've created are `SudokuGame`, `SudokuCell`, `SudokuLine`, `SudokuColumn`, `SudokuSquare` and an `abstract `class `SudokuCellGroup` that represents any set of nine `SudokuCell`s. For that reason, `SudokuLine`, `SudokuColumn`, and `SudokuSquare` inherit from this class. Each of these classes have methods to validate the Sudoku game, to search for unknown numbers, etc.

Here is the code for `SudokuCellGroup`:

C#
```using System;
using System.Collections.Generic;
using System.Text;
namespace Sudoku
{
public abstract class SudokuCellGroup
{
public abstract SudokuCell this[int index]
{
get;
}
public SudokuGame Game { get; set; }
public SudokuCellGroup(SudokuGame game)
{
this.Game = game;
}
public bool Validate()
{
List<int> ints = new List<int>();
for (int i = 0; i < 9; i++)
{
if (this[i].HasValue)
{
if (ints.Contains(this[i].Value))
return false;
else
}
}
return true;
}
public List<SudokuCell> GetPossibleCells(int value)
{
List<SudokuCell> cls = new List<SudokuCell>();
for (int i = 0; i < 9; i++)
if (this[i].GetPossibleValues().Contains(value))
return cls;
}
}
}```

Here is the code for `SudokuCell` that returns the possible numbers to place in that cell in a given moment:

C#
```public List<int> GetPossibleValues()
{
List<int> lst = new List<int>();
if (!this.HasValue)
{

for (int i = 0; i < 9; i++)
{
SudokuCell item = this.Line[i];

if (item != this)
if (item.HasValue)
if (lst.Contains(item.Value))
lst.Remove(item.Value);
}

for (int i = 0; i < 9; i++)
{
SudokuCell item = this.Column[i];
if (item != this)
if (item.HasValue)
if (lst.Contains(item.Value))
lst.Remove(item.Value);
}
for (int i = 0; i < 9; i++)
{
SudokuCell item = this.Square[i];

if (item != this)
if (item.HasValue)
if (lst.Contains(item.Value))
lst.Remove(item.Value);
}
}

return lst;
}```

## History

Written By
Instructor / Trainer
Portugal
Hello, my name is Rui Carvalho and I'm a Math teacher in Portugal. I Studied in 'Faculdade de Ciências da Universidade do Porto' and I've been programming since I was 16 years old. I'm an algorithms expert. I started in my CASIO calculator and then moved up to Visual Basic 6 (in my lovely Pentium 233 Mhz). Then I learned JAVA and c# as soon as possible. I've been programming in c# since then. For my databases I use SQL server and MySQL. I teach JAVA, C#, T-SQL to software developers (between my Math classes).
I worked in a software company for 3 years and I loved it. I spent those 3 years changing the base routines from VB6 to C# in many applications. I learned a lot about Taxes, Billing, Payments, Production,Company Management, Server Management,Synchronization,FTP, etc...
Today, unfortunately, I'm unemployed.
(Portugal is living a very very bad economic crisis)

 First Prev Next
 加油 Member 1094267021-Jul-15 16:01 Member 10942670 21-Jul-15 16:01
 Algorithm Update arpit007-from-New-Delhi9-Jun-14 19:02 arpit007-from-New-Delhi 9-Jun-14 19:02
 Re: Algorithm Update Rui Jorge Carvalho12-Aug-15 5:16 Rui Jorge Carvalho 12-Aug-15 5:16
 Bugs fixed Rui Jorge Carvalho21-Apr-14 13:33 Rui Jorge Carvalho 21-Apr-14 13:33