public static void partTwoMove(ref NodeLinkedList cupLinkedList, ref Dictionary <int, Node> cupsDict, ref List <int> dictKeys)
{
// The three cups the crab will pick up
Node firstCup = cupLinkedList.current.next;
Node secondCup = firstCup.next;
Node lastCup = secondCup.next;
// Same as partOne
int destCup = cupLinkedList.current.value - 1;
// Set now, before we move the above cups and the next cup for our 3 picked up cups changes
int newCurrentCup = lastCup.next.value;
cupLinkedList.current.next = lastCup.next;
while (true)
{
bool foundCup = false;
if (destCup < 1)
{
// Similar to what we did in partOne but without the array itself we need the dictKeys
destCup = dictKeys.Max();
}
if (destCup == firstCup.value || destCup == secondCup.value || destCup == lastCup.value)
{
destCup -= 1;
foundCup = false;
}
else
{
foundCup = true;
}
if (foundCup)
{
break;
}
}
// Set our current cup as our destCup to make it easier for when we place the cups down (left of the dest cup)
cupLinkedList.current = cupsDict[destCup];
cupLinkedList.placeCupsDown(firstCup, secondCup, lastCup, destCup);
// Once we've placed the cups down we get our new current cup, based off the old lastcup next cup
cupLinkedList.current = cupsDict[newCurrentCup];
}
public static void partTwo(ref int [] cupNumbers)
{
int numberOfCups = 1000000;
int moves = 10000000;
NodeLinkedList cupLinkedList = new NodeLinkedList();
// All credit for this idea to James and Tim
Dictionary <int, Node> cupsDict = new Dictionary <int, Node>();
foreach (int cup in cupNumbers)
{
Node n = cupLinkedList.addNewLinkedNode(cup);
cupsDict.Add(cup, n);
}
// Because we need to bulk out our cup Numbers to match 1000000 we itterate through and add i + 1.
// Because the array length = 9 and always contains numbers 1 - 9 we can just use the length as our starting point
for (int i = cupNumbers.Length; i < numberOfCups; i++)
{
Node n = cupLinkedList.addNewLinkedNode(i + 1);
cupsDict.Add(i + 1, n);
}
// We'll need this later for the dest cup values
List <int> dictKeys = cupsDict.Keys.ToList();
int firstCup = cupNumbers[0];
cupLinkedList.current = cupsDict[firstCup];
for (int i = 0; i < moves; i++)
{
partTwoMove(ref cupLinkedList, ref cupsDict, ref dictKeys);
}
cupLinkedList.current = cupsDict[1];
long firstCupValue = cupsDict[1].next.value;
long secondCupValue = cupsDict[Convert.ToInt32(firstCupValue)].next.value;
Console.WriteLine("Part Two Answer -- {0}", firstCupValue * secondCupValue);
}