protected override string Part2(string[] input)
{
var screen = ReadScreen(input);
var letters = LetterScanner.Scan(screen);
return(letters);
}
protected override string Part2(string[] input)
{
var map = PaintHull(input[0], ColorWhite);
var letters = map.Render((_, val) => val == 'W' ? '#' : ' ');
var identifier = LetterScanner.Scan(letters);
return(identifier);
}
public void CanScanAllKnownLetters()
{
// See https://www.reddit.com/r/adventofcode/comments/enxuuw/unusual_request_looking_for_ascii_art_letters/
var letters = new string[]
{
" ██ ███ ██ ███ ████ ████ ██ █ █ ███ ██ █ █ █ ██ ███ ███ ███ ███ █ █ █ █████",
"█ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █",
"█ █ ███ █ █ █ ███ ███ █ ████ █ █ ██ █ █ █ █ █ █ █ █ █ █ █ █ █ █ ",
"████ █ █ █ █ █ █ █ █ ██ █ █ █ █ █ █ █ █ █ ███ ███ ██ █ █ █ █ █ ",
"█ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ ",
"█ █ ███ ██ ███ ████ █ ███ █ █ ███ ██ █ █ ████ ██ █ █ █ ███ █ ██ █ ████"
};
var scan = LetterScanner.Scan(letters);
Assert.Equal("ABCDEFGHIJKLOPRSTUYZ", scan);
}
protected override string Part2(string[] input)
{
var layers = GetLayers(input[0]);
// Render all "pixels" by looping through each layer's similar positions and
// pick the first non-transparent value, turning '1' into black and '2' into blank.
var rendering = Enumerable.Range(0, Size)
.Select(pos => layers.Select(x => x[pos]))
.Select(x =>
{
var value = x.First(pixel => pixel != '2');
return(value == '1' ? '#' : ' ');
})
.ToArray();
var image = new string(rendering);
// Split rendering into <height> individual lines and scan them
var lines = Enumerable.Range(0, Height)
.Select(x => image.Substring(x * Width, Width));
var message = LetterScanner.Scan(lines);
return(message);
}