} // Error
/// <summary>
/// This creates a new random solution and maps that solution onto provided problem
/// </summary>
/// <param name="problem">int[][]</param>
/// <param name="rand">pass in your random object if you got one</param>
/// <returns></returns>
public static int[][] GetRandomMatrix(int[][] problem, Random rand = null)
{
Random rnd = rand ?? new Random();
// make a copy of the current puzzle
var newRandomMatrix = SudokuTool.DuplicateMatrix(problem);
for (var block = 0; block < Constants.BoardSize; ++block)
{
// fill them with 1 through 9
var corners = SudokuTool.Corner(block);
var vals = new List <int>(Constants.BoardSize);
for (var i = 1; i <= Constants.BoardSize; ++i)
{
vals.Add(i);
}
// shuffle each cell with a value from another cell
for (var k = 0; k < vals.Count; ++k)
{
var ri = rnd.Next(k, vals.Count);
var tmp = vals[k];
vals[k] = vals[ri];
vals[ri] = tmp;
}
// remove the random cell values from the known cell values
var r = corners[0];
var c = corners[1];
for (var i = r; i < r + 3; ++i)
{
for (var j = c; j < c + 3; ++j)
{
var v = problem[i][j];
if (v != 0) // a fixed starting number is assumed correct
{
vals.Remove(v);
}
}
}
// walk thru block and add the new values to the random solution output
var ptr = 0; // pointer into List
for (var i = r; i < r + 3; ++i)
{
for (var j = c; j < c + 3; ++j)
{
if (newRandomMatrix[i][j] == 0) // not occupied
{
var v = vals[ptr]; // get value from List
newRandomMatrix[i][j] = v;
++ptr; // move to next value in List
}
}
}
} // each block, k
return(newRandomMatrix);
} // RandomMatrix
} // RandomMatrix
/// <summary>
/// Randomly swap the values in two cells of a random block of the supplied matrix
/// </summary>
/// <param name="problem">the original puzzle </param>
/// <param name="matrix">the current working solution</param>
/// <param name="rand">pass in your random object if you got one</param>
/// <returns></returns>
public static int[][] EvolveMatrixAsync(int[][] problem, int[][] matrix, Random rand = null)
{
Random rnd = rand ?? new Random();
// pick a random 3x3 block,
// pick two random cells in block
// swap values
var result = SudokuTool.DuplicateMatrix(matrix);
var block = rnd.Next(0, 9); // [0,8]
//Console.WriteLine("block = " + block);
var corners = SudokuTool.Corner(block);
//Console.WriteLine("corners = " + corners[0] + " " + corners[1]);
// look for at minimum 2 cells in the neighbor matrix that might be useful in the problem
var cells = new List <int[]>();
for (var i = corners[0]; i < corners[0] + 3; ++i)
{
for (var j = corners[1]; j < corners[1] + 3; ++j)
{
//Console.WriteLine("problem " + i + " " + j + " = " + problem[i][j]);
if (problem[i][j] == 0) // a non-fixed value
{
cells.Add(new[] { i, j });
}
}
}
if (cells.Count < 2)
{
// _sb.AppendLine($"Found only {cells.Count} useful cell in the neighbor.");
throw new Exception("block " + block + " doesn't have two values to swap!");
}
// pick two. suppose there are 4 possible cells 0,1,2,3
var k1 = rnd.Next(0, cells.Count); // 0,1,2,3
var inc = rnd.Next(1, cells.Count); // 1,2,3
var k2 = (k1 + inc) % cells.Count;
//Console.WriteLine("k1 k2 = " + k1 + " " + k2);
var r1 = cells[k1][0];
var c1 = cells[k1][1];
var r2 = cells[k2][0];
var c2 = cells[k2][1];
//Console.WriteLine("r1 c1 = " + r1 + " " + c1);
//Console.WriteLine("r2 c2 = " + r2 + " " + c2);
var tmp = result[r1][c1];
result[r1][c1] = result[r2][c2];
result[r2][c2] = tmp;
return(result);
} // NeighborMatrix
} // NeighborMatrix
/// <summary>
/// for each block (3x3) in matrix2, there's a 50% chance to be added into matrix1
/// </summary>
/// <param name="matrix1">mating partner 1</param>
/// <param name="matrix2">mating partner 2</param>
/// <param name="chance">0.50 or some percential double value</param>
/// <param name="rand">pass in your random object if you got one</param>
/// <returns>a single matrix with some relationships between both provided</returns>
public static int[][] MatingResult(int[][] matrix1, int[][] matrix2, double chance = 0.50, Random rand = null)
{
Random rnd = rand ?? new Random();
var result = SudokuTool.DuplicateMatrix(matrix1);
for (var block = 0; block < 9; ++block)
{
if (rnd.NextDouble() < chance)
{
var corners = SudokuTool.Corner(block);
for (var i = corners[0]; i < corners[0] + 3; ++i)
{
for (var j = corners[1]; j < corners[1] + 3; ++j)
{
result[i][j] = matrix2[i][j];
}
}
}
}
return(result);// Task.FromResult(result);
}
