public static int SolveNQueenHelper(QueenBoard board, int row, int numSolutions)
{
if (row == board.Size)
{
return(numSolutions + 1);
}
for (var col = 0; col < board.Size; col++)
{
var successfulPlacement = board.TryPlaceQueen(row, col);
if (successfulPlacement)
{
numSolutions = SolveNQueenHelper(board, row + 1, numSolutions);
board.RemoveQueen(row, col);
}
}
return(numSolutions);
}
public static int TotalNQueens(int n)
{
var q = new QueenBoard(n);
return(SolveNQueenHelper(q, 0, 0));
}