Add day 09, part 2 (994080a0) · Commits · Roman Lacko / Advent of Code 2023

AoC/Day09.rakumod

+11 −0

Original line number	Original line	Diff line number	Diff line
	@@ -14,3 +14,14 @@ sub next-value(@measurement) {
	our sub part1(IO::Handle $in) {		our sub part1(IO::Handle $in) {
	[+] $in.lines.map(*.split(/\s/)>>.Int).map(&next-value)		[+] $in.lines.map(*.split(/\s/)>>.Int).map(&next-value)
	}		}

			sub prev-value(@measurement) {
			return 0 if @measurement.all == 0;

			my @Δ = (0 .. (@measurement.elems - 2)).map({ [-] @measurement[$^a + 1, $^a] });
			return @measurement[0] - prev-value(@Δ);
			}

			our sub part2(IO::Handle $in) {
			[+] $in.lines.map(*.split(/\s/)>>.Int).map(&prev-value)
			}