public CircularList InsertNext(CircularList node)
{
if (next == this) // only one node in the circular list
{
// Easy to handle, after the two lines of executions,
// there will be two nodes in the circular list
node.next = this;
next = node;
}
else
{
// Insert in the middle
(node.next, next) = (next, node);
}
return(node);
}
public CircularList(int value)
{
data = value;
next = this;
}
public void Traverse(CircularList node, Action <CircularList> action)
{
if (node == null)
{
node = this;
}
var startnode = node;
do
{
action(node);
node = node.next;
} while (node != startnode);
}
protected override string SolvePartTwo()
{
var max_cup = 1000000;
var ind = new Dictionary <int, CircularList>();
var head = new CircularList(_cups[0]);
ind[_cups[0]] = head;
var curr = head;
foreach (var cup in _cups)
{
if (cup == _cups[0])
{
continue;
}
curr = curr.InsertNext(cup);
ind[cup] = curr;
}
for (int i = 10; i <= max_cup; i++)
{
curr = curr.InsertNext(i);
ind[i] = curr;
}
var currCup = head;
for (int i = 0; i < 10000000; i++)
{
var c1 = currCup.DeleteNext();
var c2 = currCup.DeleteNext();
var c3 = currCup.DeleteNext();
var target = Subtract(currCup.Data, new[] { c1.Data, c2.Data, c3.Data }, max_cup);
var targetNode = ind[target];
targetNode.InsertNext(c3);
targetNode.InsertNext(c2);
targetNode.InsertNext(c1);
currCup = currCup.Next;
}
var firstStar = ind[1].Next;
var secondStar = ind[1].Next.Next;
long mul = (long)firstStar.Data * (long)secondStar.Data;
return(mul.ToString());
}
protected override string SolvePartOne()
{
var max_cup = 9;
var ind = new Dictionary <int, CircularList>();
var head = new CircularList(_cups[0]);
ind[_cups[0]] = head;
var curr = head;
foreach (var cup in _cups)
{
if (cup == _cups[0])
{
continue;
}
curr = curr.InsertNext(cup);
ind[cup] = curr;
}
var currCupNum = head.Data;
for (int i = 0; i < 100; i++)
{
var currentCup = ind[currCupNum];
var c1 = currentCup.DeleteNext();
var c2 = currentCup.DeleteNext();
var c3 = currentCup.DeleteNext();
var target = Subtract(currCupNum, new[] { c1.Data, c2.Data, c3.Data });
var targetNode = ind[target];
targetNode.InsertNext(c3);
targetNode.InsertNext(c2);
targetNode.InsertNext(c1);
currCupNum = currentCup.Next.Data;
}
var start = ind[1].Next;
var sb = new StringBuilder();
start.Traverse(start, node => sb.Append(node.Data));
return(sb.ToString().Replace("1", ""));
}
public CircularList DeleteNext()
{
if (next == this)
{
Console.WriteLine(
"\nThe node can not be deleted as there is only one node in the circular list");
return(null);
}
var node = next;
next = next.next;
return(node);
}
public CircularList()
{
data = 0;
next = this;
}