/*
* Returns the unset variable with the fewest remaining possible values.
*/
private static Variable GetNextVariable(SudokuGrid puzzleGrid)
{
Variable result = null;
foreach (var v in puzzleGrid.GetAllUnsetVariables())
{
if (result == null || v.PossibleValuesCount < result.PossibleValuesCount)
{
result = v;
}
}
return(result);
}
/*
* Initialize the possible values for each variable using the known
* initial values.
*/
private static SudokuGrid InitializeVariables(Grid <int> initialValues)
{
var puzzleGrid = new SudokuGrid(initialValues);
foreach (var unset in puzzleGrid.GetAllUnsetVariables())
{
foreach (var constraint in puzzleGrid.GetSetNeighbors(unset))
{
unset.RemovePossibleValue(constraint.Value);
}
}
return(puzzleGrid);
}