day 14, part 1

day14.ua

@@ -0,0 +1,32 @@
+$ O....#....
+$ O.OO#....#
+$ .....##...
+$ OO.#O....O
+$ .O.....O#.
+$ O.#..O.#.#
+$ ..O..#O..O
+$ .......O..
+$ #....###..
+$ #OO..#....
+TestInput ←
+
+Parse ← ⊜∘≠@\n.
+
+# the `n`th triangle number
+Triangle ← ÷2×+1.
+
+# trans: switch from sliding north to sliding west, more convenient to work with
+PartIOriginal ← (
+  ⊃(
+    -⊃(+1≡(□⊂¯1⊚)=@#|⧻⊢)
+  | ≡(□⇌∧((⍜⊢(+1)|⊂0|∘)⊗⊙"O#")⊙[0])
+  )⍉
+  /+≡(/+-≡⊃(Triangle-:|Triangle)∩°□)
+)
+
+SlideLeft ← ≡(⍜⊜□(≡(□⊐/⊂⊕□∩°□)=@..)≠@#.)
+PartI ← /+♭×⊃(¤-⇡.⧻⊢|=@O)SlideLeft⍉
+
+PartI Parse TestInput
+
+PartI Parse &fras "day14.in"