private static (int destValue, List <Cup> nextThree) FindDestValue(int currCupValue, Cup curr, int max)
{
var nextThree = new List <Cup> {
curr.Next, curr.Next.Next, curr.Next.Next.Next
};
curr.Next = nextThree[2].Next;
nextThree[2].Next.Prev = curr;
nextThree[0].Prev = null;
nextThree[2].Next = null;
int destValue = curr.Value;
destValue--; // zero based
for (int i = 0; i < 4; i++)
{
if (destValue == 0)
{
destValue += max;
destValue--;
destValue %= max;
}
else
{
destValue--;
}
if (nextThree.All(x => x.Value != destValue + 1))
{
return(destValue + 1, nextThree);
}
}
throw new ApplicationException();
}
static void PartTwo(string input)
{
var map = new Dictionary <int, Cup>();
Cup head = null;
Cup curr = null;
foreach (var cupVal in input)
{
var cup = new Cup(cupVal - '0');
map.Add(cupVal - '0', cup);
if (head == null && curr == null)
{
head = cup;
curr = cup;
}
else
{
curr.Next = cup;
cup.Prev = curr;
curr = cup;
}
}
int maxCups = 1000000;
for (int i = 10; i <= maxCups; i++)
{
var cup = new Cup(i);
curr.Next = cup;
cup.Prev = curr;
curr = cup;
map.Add(i, cup);
}
curr.Next = head;
head.Prev = curr;
curr = head;
// Play game
var maxTurns = 10000000;
for (int t = 0; t < maxTurns; t++)
{
int currCupValue = curr.Value;
var(destValue, nextThree) = FindDestValue(currCupValue, curr, maxCups);
var destCup = map[destValue];
nextThree[2].Next = destCup.Next;
nextThree[0].Prev = destCup;
destCup.Next.Prev = nextThree[2];
destCup.Next = nextThree[0];
curr = curr.Next;
}
var p12 = 0;
var p1Node = map[1];
for (int i = 0; i < 8; i++)
{
p1Node = p1Node.Next;
Console.WriteLine(p1Node.Value);
p12 *= 10;
p12 += p1Node.Value;
}
Console.WriteLine(p12);
var prevValue = map[1].Next.Value;
var nextValue = map[1].Next.Next.Value;
Console.WriteLine(prevValue);
Console.WriteLine(nextValue);
p2 = prevValue * nextValue;
}