public Day21Pattern[][] BreakIntoSquares()
{
var eachSquareSize = (Size % 2 == 0 ? 2 : 3);
Day21Pattern[][] squares = new Day21Pattern[Size / eachSquareSize][];
for (int i = 0; i < Size / eachSquareSize; i++)
{
squares[i] = new Day21Pattern[Size / eachSquareSize];
for (int j = 0; j < Size / eachSquareSize; j++)
{
bool[][] thisSquarePattern = new bool[eachSquareSize][];
for (int k = 0; k < eachSquareSize; k++)
{
thisSquarePattern[k] = new bool[eachSquareSize];
for (int l = 0; l < eachSquareSize; l++)
{
thisSquarePattern[k][l] = Pattern[i * eachSquareSize + k][j * eachSquareSize + l];
}
squares[i][j] = new Day21Pattern(thisSquarePattern);
}
}
}
return(squares);
}
public Day21Pattern EnhancePattern(Day21Pattern pattern)
{
var encodedPatterns = new[]
{
pattern.ToEncodedPattern(),
pattern.FlipHorizontal().ToEncodedPattern(),
pattern.FlipHorizontal().RotateLeft().ToEncodedPattern(),
pattern.FlipVertical().RotateRight().ToEncodedPattern(),
pattern.FlipVertical().RotateLeft().ToEncodedPattern(),
pattern.FlipHorizontal().RotateRight().ToEncodedPattern(),
pattern.FlipVertical().ToEncodedPattern(),
pattern.RotateLeft().ToEncodedPattern(),
pattern.RotateLeft().RotateLeft().ToEncodedPattern(),
pattern.RotateRight().ToEncodedPattern()
};
foreach (var encodedPattern in encodedPatterns)
{
if (rules.ContainsKey(encodedPattern))
{
return(new Day21Pattern(rules[encodedPattern]));
}
}
throw new InvalidOperationException("Oops, found no matching rule! Something went wrong...");
}
public int Solve()
{
var pattern = new Day21Pattern();
var ruleBook = new Day21RuleBook(Input);
for (int i = 0; i < 18; i++)
{
Console.WriteLine(pattern);
Console.WriteLine("=======");
var nextPatterns = pattern.BreakIntoSquares();
var enhancedPatterns =
nextPatterns.Select(patternRow => patternRow.Select(p => ruleBook.EnhancePattern(p)).ToArray()).ToArray();
var combinedPattern = new Day21Pattern(enhancedPatterns);
pattern = combinedPattern;
}
Console.WriteLine(pattern);
return(pattern.CountOnPixels()); //240 too high, bother. 210 still too high; I must have misunderstood something as order of rotation / flipping seems to matter. 206 also wrong
}