public DataNode(ColumnNode column, int id)
{
Column = column;
ID = id;
Left = this;
Right = this;
Up = this;
Down = this;
}
public ColumnNode choose_next_column()
{
int size = int.MaxValue;
ColumnNode nextCol = new ColumnNode(-1);
ColumnNode j = header.Right.Column;
while (j != header)
{
if (j.Size < size)
{
nextCol = j;
size = j.Size;
}
j = j.Right.Column;
}
return(nextCol);
}
public ColumnNode createLinkedList(int[,] grid)
{
//create a circular doubly linked link representing the given sudoku
var columns = new List <ColumnNode>();
for (int col_ind = 0; col_ind < 324; col_ind++)
{
ColumnNode col = new ColumnNode(col_ind);
col.Right = h;
col.Left = h.Left;
h.Left.Right = col;
h.Left = col;
columns.Add(col);
}
for (int x = 0; x < 9; x++)
{
for (int y = 0; y < 9; y++)
{
if (grid[x, y] == 0)
{
for (int d = 0; d < 9; d++)
{
//this cell is blank so add all possibilities
form_links(columns, x, y, d);
}
}
else
{
//clue exists in this location so add only for that possibility
int d = grid[x, y] - 1;
form_links(columns, x, y, d);
}
}
}
return(h);
}
public DLX(ColumnNode h)
{
this.h = h;
}
public AlgorithmX(ColumnNode h)
{
header = h;
}