private static bool Solve(SudokuBoard board, int i, int j)
{
BoardStatus status = board.Check();
if (status == BoardStatus.Solved)
{
return(true);
}
if (status == BoardStatus.Unsolvable)
{
return(false);
}
int iNext = i;
int jNext = j + 1;
if (jNext >= board.size)
{
jNext = 0;
iNext++;
}
if (board.IsFixedNumber(i, j))
{
return(Solve(board, iNext, jNext));
}
else
{
for (int n = 1; n <= board.size; n++)
{
board.SetNumber(i, j, n);
if (Solve(board, iNext, jNext))
{
return(true);
}
}
board.SetNumber(i, j, 0);
return(false);
}
}