Day 01

day01/default.nix

@@ -0,0 +1,32 @@
+{ pkgs, lib, ... }:
+
+with lib;
+
+let 
+  elves = pipe (builtins.readFile ./input.txt) [
+    (splitString "\n\n")
+    (map (splitString "\n"))
+    (map (map toInt))
+    (map (fold add 0))
+  ];
+
+  answer1 = toString (fold max (-1) elves);
+
+  max3 = abc: x: if x >= abc.a then { a = x; b = abc.a; c = abc.b; } else
+                 if x >= abc.b then { a = abc.a; b = x; c = abc.b; } else
+                 if x >= abc.c then { inherit (abc) a b; c = x; } else
+                 abc;
+
+  answer2 = pipe elves [
+    (foldl max3 { a = -1; b = -1; c = -1; })
+    (abc: abc.a + abc.b + abc.c)
+    toString
+  ];
+
+in pkgs.writeText "answers" ''
+  Task1:
+    ${answer1}
+
+  Task2:
+    ${answer2}
+''