//Алгоритм Решения задачи с использованием Dancing Links
public bool Solve()
{
if (header_root.right == header_root)
{
return(true);
}
bool flag = true;
for (var head = header_root.right; head != header_root; head = head.right)
{
if (((Nodes.HeaderNode)head).isNodeID == false)
{
flag = false;
}
}
if (flag)
{
return(true);
}
Nodes.HeaderNode header = ShortColumn();
Remove(header);
Nodes.Node node = header.down;
n++;
while (node != header)
{
solution_array.Add(node);
for (Nodes.Node node_it = node.right; node_it != node; node_it = node_it.right)
{
Remove(node_it.header);
}
if (Solve())
{
return(true);
}
solution_array.RemoveAt(solution_array.Count - 1);
header = node.header;
for (Nodes.Node node_it = node.left; node_it != node; node_it = node_it.left)
{
Restore(node_it.header);
}
node = node.down;
}
Restore(header);
return(false);
}
//Восстановление корневой вершины
private void Restore(Nodes.HeaderNode header)
{
for (Nodes.Node row = header.up; row != header; row = row.up)
{
for (Nodes.Node col = row.left; col != row; col = col.left)
{
col.header.count_nodes++;
col.down.up = col;
col.up.down = col;
}
}
header.right.left = header;
header.left.right = header;
}
//Метод создания корневых вершин
public void CreateHeadersNodes(int count)
{
header_root = new Nodes.HeaderNode();
for (int i = 0; i < count; i++)
{
Nodes.HeaderNode header_node = new Nodes.HeaderNode();
headers_columns.Add(header_node);
header_node.left = header_root.left;
header_node.right = header_root;
header_root.left.right = header_node;
header_root.left = header_node;
}
}
//Удаления корневой вершины
private void Remove(Nodes.HeaderNode header)
{
header.right.left = header.left;
header.left.right = header.right;
for (Nodes.Node row = header.down; row != header; row = row.down)
{
for (Nodes.Node col = row.right; col != row; col = col.right)
{
col.down.up = col.up;
col.up.down = col.down;
col.header.count_nodes--;
}
}
}
//Метод получения столбцы содержаший наименьшее кол-во единиц
private Nodes.HeaderNode ShortColumn()
{
Nodes.HeaderNode column = null;
int min = int.MaxValue;
for (Nodes.HeaderNode col_header = (Nodes.HeaderNode)header_root.right; col_header != header_root; col_header = (Nodes.HeaderNode)col_header.right)
{
if ((col_header.count_nodes < min) && (col_header.isNodeID == false))
{
min = col_header.count_nodes;
column = col_header;
}
}
return(column);
}
