private static Pot ParseInitialState(string initialState)
{
var pot0 = Pot.LeftmostPot(0, initialState[15] == '#');
var rightmostPot = pot0;
foreach (var pot in initialState.Skip(16))
{
rightmostPot = rightmostPot.AddToTheRight(pot == '#');
}
return(pot0);
}
private static Pot NextGeneration(Pot leftmostPot, Dictionary <byte, bool> spreadRules)
{
var runningPattern = new Queue <bool>(new bool[] { false, false, false, false });
var index = leftmostPot.Index - 2;
var currentPotPreviousGeneration = leftmostPot;
Pot currentPotNextGeneration = null;
Pot leftmostPotNextGeneration = null;
int?numberOfPotsRemainingToGenerate = null;
while (true)
{
if (numberOfPotsRemainingToGenerate == 0)
{
return(leftmostPotNextGeneration.Trim());
}
if (currentPotPreviousGeneration == null)
{
// We are at the end.
runningPattern.Enqueue(false);
if (numberOfPotsRemainingToGenerate.HasValue)
{
numberOfPotsRemainingToGenerate--;
}
else
{
numberOfPotsRemainingToGenerate = 3;
}
}
else
{
runningPattern.Enqueue(currentPotPreviousGeneration.HasPlant);
currentPotPreviousGeneration = currentPotPreviousGeneration.PotToTheRight;
}
var spreadKey = CalculateSpreadKey(runningPattern);
spreadRules.TryGetValue(spreadKey, out var hasPlant);
if (currentPotNextGeneration == null)
{
currentPotNextGeneration = Pot.LeftmostPot(index, hasPlant);
leftmostPotNextGeneration = currentPotNextGeneration;
}
else
{
currentPotNextGeneration = currentPotNextGeneration.AddToTheRight(hasPlant);
}
index++;
runningPattern.Dequeue();
}
}