77 lines
1.6 KiB
Nix
77 lines
1.6 KiB
Nix
{lib, ...}: rawContent: rec {
|
|
content = lib.strings.removeSuffix "\n" rawContent;
|
|
|
|
toLines = lib.strings.splitString "\n";
|
|
toLevels = map ( line: line
|
|
|> lib.strings.splitString " "
|
|
|> map lib.strings.toInt
|
|
)
|
|
;
|
|
isSafe = builtins.foldl'
|
|
({prev ? null, inc ? null, safe}: next:
|
|
if !safe then {inherit safe;} else
|
|
if prev == null then {prev = next; inherit safe;} else
|
|
let
|
|
diff = next - prev;
|
|
safeDiff = abs diff > 0 && abs diff <= 3;
|
|
isInc = next > prev;
|
|
in {
|
|
prev = next;
|
|
safe = safeDiff && ( isInc == inc || isNull inc );
|
|
inc = isInc;
|
|
}
|
|
)
|
|
{safe = true;};
|
|
|
|
abs = n: if n > 0 then n else -n;
|
|
|
|
countSafety = lib.lists.count (level: level.safe);
|
|
|
|
getPart1Result = input: input
|
|
|> toLines
|
|
|> toLevels
|
|
|> map isSafe
|
|
|> countSafety
|
|
;
|
|
|
|
part1result = getPart1Result content;
|
|
|
|
excluding = l: i: let
|
|
len = builtins.length l;
|
|
before = lib.sublist 0 (i) l;
|
|
after = lib.sublist (i + 1) (len - 1) l;
|
|
in before ++ after
|
|
;
|
|
|
|
dampLevels = l: let
|
|
len = builtins.length l;
|
|
range = lib.range 0 (len - 1);
|
|
toTest = map (excluding l) range
|
|
;
|
|
in toTest;
|
|
|
|
anySafety = builtins.any (level: level.safe);
|
|
|
|
dampSafety = level: level
|
|
|> dampLevels
|
|
|> map isSafe
|
|
|> anySafety
|
|
;
|
|
|
|
isSafeWithDamp = level:
|
|
( isSafe level ).safe || ( dampSafety level )
|
|
;
|
|
|
|
countSafeWithDamp = levels: levels
|
|
|> map isSafeWithDamp
|
|
|> lib.count (a: a == true)
|
|
;
|
|
|
|
part2result = content
|
|
|> toLines
|
|
|> toLevels
|
|
|> countSafeWithDamp
|
|
;
|
|
|
|
}
|