private static void CupShuffle(int currentCup, Dictionary <int, Cup> cups, int movesToComplete)
{
for (int move = 0; move < movesToComplete; move++)
{
var cup1 = cups[currentCup].Next;
var cup2 = cup1.Next;
var cup3 = cup2.Next;
var label = cups[currentCup].Value;
Cup destinationCup = null;
while (destinationCup == null || destinationCup.Value == cup1.Value || destinationCup.Value == cup2.Value || destinationCup.Value == cup3.Value)
{
label--;
if (label < _minValue)
{
label = _maxValue;
}
destinationCup = cups[label];
}
var cn = cup3.Next;
cups[currentCup].Next = cn;
cn.Previous = cups[currentCup];
var dn = destinationCup.Next;
cup3.Next = dn;
dn.Previous = cup3;
destinationCup.Next = cup1;
cup1.Previous = destinationCup;
currentCup = cups[currentCup].Next.Value;
}
}
private static void CupShuffle(int currentCup, Dictionary <int, Cup> cups, int moves)
{
for (int move = 0; move < moves; move++)
{
var cup1 = cups[currentCup].Next;
var cup2 = cup1.Next;
var cup3 = cup2.Next;
var label = cups[currentCup].Value;
Cup destinationCup = null;
while (destinationCup == null || destinationCup.Value == cup1.Value || destinationCup.Value == cup2.Value || destinationCup.Value == cup3.Value)
{
label--;
if (label < minValue)
{
label = maxValue;
}
destinationCup = cups[label];
}
cups[currentCup].Next = cup3.Next;
(cup3.Next).Previous = cups[currentCup];
cup1.Previous = destinationCup;
cup3.Previous = cups[currentCup];
cup3.Next = destinationCup.Next;
destinationCup.Next = cup1;
currentCup = cups[currentCup].Next.Value;
}
}
public void Place(Cup cups)
{
Cup first = cups;
Cup last = cups.Prev;
last.Connect(Next);
Connect(first);
}
public IEnumerable <int> Labels()
{
yield return(Label);
for (Cup cup = Next; cup != this; cup = cup.Next)
{
yield return(cup.Label);
}
}
public Cup Pickup()
{
Cup first = Next;
Cup last = first.Next.Next;
Connect(last.Next);
last.Connect(first);
return(first);
}
private static void ArrangeCups(int[] cupArray, Dictionary <int, Cup> cups)
{
for (var cupIndex = 0; cupIndex < cupArray.Length; cupIndex++)
{
var value = cupArray[cupIndex];
cups.Add(value, new Cup()
{
Value = value,
Previous = cupIndex > 0 ? cups[cupArray[cupIndex - 1]] : null,
Next = null
});
if (cupIndex > 0)
{
cups[cupArray[cupIndex - 1]].Next = cups[cupArray[cupIndex]];
}
if (value > _maxValue)
{
_maxValue = value;
}
if (value < _minValue)
{
_minValue = value;
}
}
Cup previous = cups[cupArray[cupArray.Length - 1]];
int nextValue = _maxValue + 1;
while (cups.Count < ONE_MILLION)
{
var nextCup = new Cup()
{
Value = nextValue,
Previous = previous,
Next = null
};
cups.Add(nextValue, nextCup);
previous.Next = nextCup;
previous = nextCup;
if (nextValue > _maxValue)
{
_maxValue = nextValue;
}
nextValue++;
}
cups[cupArray[0]].Previous = cups[nextValue - 1];
cups[nextValue - 1].Next = cups[cupArray[0]];
}
static void Part1(Cups cups)
{
for (int i = 0; i < 100; ++i)
{
cups.Move();
}
// zero based indexing
Cup one = cups.Find(0);
Console.WriteLine("Part 1: {0}", string.Join("", one.Labels().Select(label => label + 1).Skip(1)));
}
static void Part2(Cups cups)
{
for (int i = 0; i < 10000000; ++i)
{
cups.Move();
}
Cup one = cups.Find(0);
long next0 = one.Next.Label + 1;
long next1 = one.Next.Next.Label + 1;
Console.WriteLine("Part 2: {0}", next0 * next1);
}
public void Move()
{
Cup pickup = _current.Pickup();
HashSet <int> pickupLabels = new(pickup.Labels());
int destLabel = (_current.Label + _cups.Count - 1) % _cups.Count;
while (pickupLabels.Contains(destLabel))
{
destLabel = (destLabel + _cups.Count - 1) % _cups.Count;
}
_cups[destLabel].Place(pickup);
_current = _current.Next;
}
public void Connect(Cup next)
{
Next = next;
next.Prev = this;
}
