public QueenList GetSolution(ushort numberOfQueens)
{
Queen queen = null;
Square testSquare;
ushort rank, column;
bool removeLast = false;
var result = new QueenList();
bool goodSquare;
while (result.Count < numberOfQueens)
{
queen = removeLast ? result[result.Count - 1] : new Queen(result.ReservedSquares.Select(square => square.Rank));
do
{
if (removeLast && queen.TriedColumns.Count < numberOfQueens)
{
rank = queen.Square.Rank;
}
else
{
rank = rankProvider.GetNextElement(queen.TriedRanks, numberOfQueens);
}
if (rank != UInt16.MaxValue)
{
if (removeLast)
{
result.RemoveAt(result.Count - 1);
removeLast = false;
}
else
{
queen.ClearTriedColumns(result.ReservedSquares.Select(square => square.Column));
}
do
{
column = columnProvider.GetNextElement(queen.TriedColumns, numberOfQueens);
if (column != UInt16.MaxValue)
{
testSquare = new Square(rank, column);
goodSquare = result.IsGoodSquare(testSquare);
}
else
{
goodSquare = false;
testSquare = null;
}
}while (ContinueSearch(numberOfQueens, queen.TriedColumns.Count, goodSquare));
}
else
{
goodSquare = false;
testSquare = null;
result.RemoveAt(result.Count - 1);
}
} while (ContinueSearch(numberOfQueens, queen.TriedRanks.Count, goodSquare));
if (goodSquare)
{
queen.Square = testSquare;
result.Add(queen);
}
else
{
removeLast = true;
}
}
return(result);
}