public static Microsoft.SolverFoundation.Services.Decision[] CreateVariables(this Microsoft.SolverFoundation.Services.Model model, Microsoft.SolverFoundation.Services.Domain digits)
{
var grid = new Microsoft.SolverFoundation.Services.Decision[81];
for (int i = 0; i < 81; i++)
{
grid[i] = new Microsoft.SolverFoundation.Services.Decision(digits, $"cell_{i}");
model.AddDecision(grid[i]);
}
return(grid);
}
public static void AddHints(this Microsoft.SolverFoundation.Services.Model model, Microsoft.SolverFoundation.Services.Decision[] x, IEnumerable <GridCell> hints)
{
// Constrains each cell we know the value of to that specific value
if (hints != null)
{
foreach (var hint in hints)
{
int index = (hint.Y * 9) + hint.X;
model.AddConstraint($"Cell_{hint.X}_{hint.Y}_Equals_{hint.Value}", x[index] == hint.Value);
}
}
}
public static void CreateConstraints(this Microsoft.SolverFoundation.Services.Model model, Microsoft.SolverFoundation.Services.Decision[] grid)
{
for (int group = 0; group < 9; group++)
{
// Create row constraints
var row = new List <Microsoft.SolverFoundation.Services.Decision>();
for (int i = 0; i < 9; i++)
{
int index = (group * 9) + i;
row.Add(grid[index]);
}
model.AddConstraint($"Row{group}_AllDifferent", Microsoft.SolverFoundation.Services.Model.AllDifferent(row.ToArray()));
// Create column constraints
var col = new List <Microsoft.SolverFoundation.Services.Decision>();
for (int i = 0; i < 9; i++)
{
int index = (i * 9) + group;
col.Add(grid[index]);
}
model.AddConstraint($"Col{group}_AllDifferent", Microsoft.SolverFoundation.Services.Model.AllDifferent(col.ToArray()));
// Create region constraints
int regionStartX = (group % 3) * 3;
int regionStartY = (group / 3) * 3;
var region = new List <Microsoft.SolverFoundation.Services.Decision>();
for (int i = 0; i < 9; i++)
{
int deltaX = (i % 3);
int deltaY = (i / 3);
int xLoc = regionStartX + deltaX;
int yLoc = regionStartY + deltaY;
int index = (yLoc * 9) + xLoc;
region.Add(grid[index]);
}
model.AddConstraint($"Region{group}_AllDifferent", Microsoft.SolverFoundation.Services.Model.AllDifferent(region.ToArray()));
}
}
