From 311b69fcf28ab9c92123b792b97ba4569161dfb6 Mon Sep 17 00:00:00 2001
From: Panadestein <rpana92@gmail.com>
Date: Wed, 4 Dec 2024 10:58:34 +0100
Subject: [PATCH] feat: added day 4.

---
 src/aoc24.org     | 18 ++++++++++++++++--
 src/bqn/aoc24.bqn | 12 ++++++++++--
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/src/aoc24.org b/src/aoc24.org
index b3805cb..d1aa809 100644
--- a/src/aoc24.org
+++ b/src/aoc24.org
@@ -29,7 +29,7 @@ to get more context. Each day corresponds to a function, and the following top-l
 additional purpose of tracking my progress:
 
 #+begin_src bqn :tangle ./bqn/aoc24.bqn :results none
-  ⟨I, II, III⟩⇐
+  ⟨I, II, III, IV⟩⇐
 #+end_src
 
 These definitions and imports are shared by the various puzzles:
@@ -78,7 +78,7 @@ These definitions and imports are shared by the various puzzles:
 #+begin_src bqn :tangle ./bqn/aoc24.bqn
   III ← {
     mem ← •FChars Input𝕩
-    prg ← mem/˜1{·𝕊¯1:0;·𝕊1:1;𝕨𝕊0:𝕨}`-´"do()"‿"don't()"(≢∘⊢↑⍷)¨<mem
+    prg ← mem/˜1=×∘+`2×-´"do()"‿"don't()"(≢∘⊢↑⍷)¨<mem
     mul‿cmd ← {(12↑↓⟜𝕩)¨4+/"mul("(≢∘⊢↑⍷)𝕩}¨mem‿prg
     V ← {
       l‿r←⊑⎊0¨1(↑⋈↓)','Split𝕩
@@ -93,6 +93,20 @@ These definitions and imports are shared by the various puzzles:
 : ⟨ 165225049 108830766 ⟩
 
 ** IV
+
+#+begin_src bqn :tangle ./bqn/aoc24.bqn
+  IV ← {
+    inp ← >•FLines Input 𝕩
+    t‿ts ← ⟨"XMAS"‿"SAMX", "MSAMS"‿"SMASM"‿"SSAMM"‿"MMASS"⟩
+    eins ⇐ +´t(≢∘⊢↑⍷){+´⟨⥊+´𝕨𝔽¨<𝕩, ⥊+´𝕨𝔽¨<⍉𝕩, ∾+˝𝕨𝔽⌜𝔾𝕩, ∾+˝𝕨𝔽⌜𝔾⌽⍉𝕩⟩}((+⌜´↕¨∘≢)⊸⊔) inp
+    zwei ⇐ +´⥊{ts≡¨<(⌽˘⊸∨=⌜˜↕3)/○⥊𝕩}⎉2 3‿3↕inp
+  }
+  IV _is 4
+#+end_src
+
+#+RESULTS:
+: ⟨ 2397 1824 ⟩
+
 ** V
 ** VI
 ** VII
diff --git a/src/bqn/aoc24.bqn b/src/bqn/aoc24.bqn
index 61898c5..48804bc 100644
--- a/src/bqn/aoc24.bqn
+++ b/src/bqn/aoc24.bqn
@@ -1,4 +1,4 @@
-⟨I, II, III⟩⇐
+⟨I, II, III, IV⟩⇐
 
 Split ← (¬-˜⊢×·+`»⊸>)∘≠⊔⊢
 Input ← {"../supp/aoc/2024/"∾".inp"∾˜•Fmt𝕩}
@@ -22,7 +22,7 @@ II _is 2
 
 III ← {
   mem ← •FChars Input𝕩
-  prg ← mem/˜1{·𝕊¯1:0;·𝕊1:1;𝕨𝕊0:𝕨}`-´"do()"‿"don't()"(≢∘⊢↑⍷)¨<mem
+  prg ← mem/˜1=×∘+`2×-´"do()"‿"don't()"(≢∘⊢↑⍷)¨<mem
   mul‿cmd ← {(12↑↓⟜𝕩)¨4+/"mul("(≢∘⊢↑⍷)𝕩}¨mem‿prg
   V ← {
     l‿r←⊑⎊0¨1(↑⋈↓)','Split𝕩
@@ -31,3 +31,11 @@ III ← {
   eins‿zwei ⇐ (+´V¨)¨ mul‿cmd
 }
 III _is 3
+
+IV ← {
+  inp ← >•FLines Input 𝕩
+  t‿ts ← ⟨"XMAS"‿"SAMX", "MSAMS"‿"SMASM"‿"SSAMM"‿"MMASS"⟩
+  eins ⇐ +´t(≢∘⊢↑⍷){+´⟨⥊+´𝕨𝔽¨<𝕩, ⥊+´𝕨𝔽¨<⍉𝕩, ∾+˝𝕨𝔽⌜𝔾𝕩, ∾+˝𝕨𝔽⌜𝔾⌽⍉𝕩⟩}((+⌜´↕¨∘≢)⊸⊔) inp
+  zwei ⇐ +´⥊{ts≡¨<(⌽˘⊸∨=⌜˜↕3)/○⥊𝕩}⎉2 3‿3↕inp
+}
+IV _is 4