Business Objects & Instantiation

Visualization

The image below visualizes the data created below. In this example the board size is 9 and the white fields are already set.
The purple fields have to be determined by the solver according to the constraints in the model we will define in the following step.

Program instance

Instantiation of the pre set numbers the board size and the sections, as well as the Solver and an empty Solution.
Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using OPTANO.Modeling.Optimization.Solver.Gurobi810;

namespace Sudoku
{

    using OPTANO.Modeling.Optimization;
    using OPTANO.Modeling.Optimization.Configuration;


    /// <summary>
    /// program solving a Sudoku
    /// </summary>
    class Program
    {
        /// <summary>
        /// The main method
        /// </summary>
        /// <param name="args">
        /// no arguments required
        /// </param>
        static void Main(string[] args)
        {
            
            var size = Enumerable.Range(0, 9).ToList();
            var section = size.GroupBy(s => s / 3);

            // you may manipulate the following game, which is the initial state of the Sudoku to your liking
            // note: obviously not observing the rules of Sudoku here makes the problem infeasible
            var game = new int?[,] {
                    //  0    1      2     3     4    5     6     7     8 
                    { null,    3, null, null, null, null, null, null, null },
                    { null, null, null,    1,    9,    5, null, null, null },
                    { null, null,    8, null, null, null, null,    6, null },

                    {    8, null, null, null,    6, null, null, null, null },
                    {    4, null, null,    8, null, null, null, null,    1 },
                    { null, null, null, null,    2, null, null, null, null },

                    { null,    6, null, null, null, null,    2,    8, null },
                    { null, null, null,    4,    1,    9, null, null,    5 },
                    { null, null, null, null, null, null, null,    7, null },
                };

            // Use long names for easier debugging/model understanding.
            var config = new Configuration();
            config.NameHandling = NameHandlingStyle.UniqueLongNames;
            config.ComputeRemovedVariables = true;
            using (var scope = new ModelScope(config))
            {
                // create a model, based on given data and the model scope
                var sudokuModel = new SudokuModel(size, section, game);

                // get a solver instance, change your solver
                using (var solver = new GurobiSolver())
                {
                    // solve the model
                    var solution = solver.Solve(sudokuModel.Model);

                    // print objective and variable decisions
                    Console.WriteLine("Result: ");
                    foreach (var row in size)
                    {
                        foreach (var col in size)
                        {
                            foreach (var value in size)
                            {
                                if (sudokuModel.field[col, row, value].Value > 0)
                                {
                                    Console.Write(string.Format("   {0}", value + 1));
                                }
                            }
                            if ((col + 1) % 3 == 0)
                            {
                                Console.Write("  ");
                            }
                        }

                        if ((row + 1) % 3 == 0)
                        {
                            Console.WriteLine();
                        }

                        Console.WriteLine();
                    }

                    Console.ReadLine();
                }
            }
        }
    }
}

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