private Node solve(int location, int flags, Node route, int cnt)
{
if (cnt == 6) {
var lastNode = route.Next.Next.Next.Next.Next;
Debug.Assert(lastNode != null);
Debug.Assert(lastNode.Next == null);
int head = lastNode.Value / 100;
if (location == head)
return route;
else
return null;
}
var links = table[location];
if (links == null)
return null;
foreach (var link in links) {
if ((flags & (1 << link.Kind)) != 0)
continue;
// visited
var nextFlag = flags | (1 << link.Kind);
var nextRoute = new Node(location * 100 + link.Next, route);
var result = solve(link.Next, nextFlag, nextRoute, cnt + 1);
if (result != null)
return result;
}
return null;
}
private void Write(Node node)
{
int sum = 0;
Node n = node;
while (n != null) {
sum += n.Value;
n = n.Next;
}
Console.WriteLine(sum + " : " + node);
}
public Node(int value, Node next)
{
Debug.Assert(1000 < value && value <= 10000);
this.Value = value;
this.Next = next;
}