public bool Equals(ProfessorChecker other)
{
if (ReferenceEquals(null, other)) return false;
if (ReferenceEquals(this, other)) return true;
return other._id.Equals(_id);
}
private IEnumerable<ProfessorChecker> FindMatchingChecker(ProfessorChecker[] solution, int solutionIndex, ProfessorChecker[] checkers)
{
var unused = checkers.Except(solution).ToList();
var thisIndex = solutionIndex + 1;
foreach (var unusedProfessorChecker in unused)
{
for (int i = 0; i < 4; i++)
{
if (thisIndex < 4) //first row
{
var leftChecker = solution[solutionIndex];
if (leftChecker.Right.Color == unusedProfessorChecker.Left.Color &&
leftChecker.Right.BodyPart != unusedProfessorChecker.Left.BodyPart)
{
yield return unusedProfessorChecker.Clone();
}
}
else if (thisIndex % 4 == 0) //first column, in any other row
{
var topChecker = solution[thisIndex - 4];
if (topChecker.Bottom.Color == unusedProfessorChecker.Top.Color
&& topChecker.Bottom.BodyPart != unusedProfessorChecker.Top.BodyPart)
{
yield return unusedProfessorChecker.Clone();
}
}
else //2nd-4th column in 2nd-4th row
{
var leftChecker = solution[thisIndex - 1];
var topChecker = solution[thisIndex - 4];
if (leftChecker.Right.Color == unusedProfessorChecker.Left.Color &&
leftChecker.Right.BodyPart != unusedProfessorChecker.Left.BodyPart &&
topChecker.Bottom.Color == unusedProfessorChecker.Top.Color &&
topChecker.Bottom.BodyPart != unusedProfessorChecker.Top.BodyPart)
{
yield return unusedProfessorChecker.Clone();
}
}
unusedProfessorChecker.TurnRight();
}
}
}
public IEnumerable<ProfessorChecker[]> Solve()
{
var bag = new ConcurrentBag<ProfessorChecker[]>();
_checkers.AsParallel().ForAll(checker =>
{
var checkers = _checkers.Select(c => c.Clone()).ToArray();
for (int i = 0; i < 4; i++)
{
var board = new ProfessorChecker[16];
board[0] = checker;
var solutions = BuildSolutionRecursively(board, 0, checkers).ToList();
foreach (var solution in solutions)
{
bag.Add(solution);
}
checker.TurnRight();
}
});
return bag;
}
private IEnumerable<ProfessorChecker[]> BuildSolutionRecursively(ProfessorChecker[] board, int solutionIndex, ProfessorChecker[] checkers)
{
var nextIndex = solutionIndex + 1;
var matchingCheckers = FindMatchingChecker(board, solutionIndex, checkers).ToList();
foreach (var nextChecker in matchingCheckers)
{
board[nextIndex] = nextChecker;
if (nextIndex == 15)
{
yield return board.Select(pc => pc.Clone()).ToArray();
}
if (nextIndex < 15)
{
foreach (var solution in BuildSolutionRecursively(board, nextIndex, checkers))
{
yield return solution;
}
}
board[nextIndex] = null;
}
}
public ProfessorGameSolver(ProfessorChecker[] checkers)
{
if (checkers.Length != 16)
throw new ArgumentOutOfRangeException("checkers");
_checkers = checkers;
}
