From fa17b27096c39a6e66824c54de5a93d300dd75a3 Mon Sep 17 00:00:00 2001
From: rhiannon morris <rhi@rhiannon.website>
Date: Sat, 3 Dec 2022 08:39:34 +0100
Subject: [PATCH] =?UTF-8?q?day3=20bqn=20=F0=9F=A5=93?=
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---
 aoc.bqn | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/aoc.bqn b/aoc.bqn
index 4df2e71..2f9325f 100644
--- a/aoc.bqn
+++ b/aoc.bqn
@@ -4,12 +4,20 @@ Sub ⇐ {a‿b𝕊𝕩:b↑a↓𝕩}
 # e Split xs: split xs on occurrences of e (default 0)
 Split ⇐ {(⊏ ∾ 1⊸↓¨∘(1⊸↓)) Sub⟜𝕩¨ (» ⋈¨ ⊢-») /𝕨=𝕩∾(𝕨⊣⟜0↩)}
 
+# n Chunk xs: split into chunks of length n (the last one might be smaller)
+Chunk ⇐ {(⌊𝕨÷˜↕≠𝕩)⊔𝕩}
+
 Day1 ⇐ (⊑ ⋈ (+´3⊸↑))∘(∨+´¨)∘Split∘(•BQN⎊0¨)∘•FLines
 
 Day2 ⇐ {
   B ← ⊣ (A ← {1+𝕩+3×3|1+𝕩-𝕨}) {3|𝕨+𝕩-1}
   +´˘⍉ (A≍B)´∘{a‿s‿b:⟨a-'A',b-'X'⟩}˘ >•FLines 𝕩
 }
-•Show Day2 ⊑•args
 
-# day 3 maybe later
+Day3 ⇐ {
+  Prio ← ⊢ - ⊑⟜"`&"∘(≤⟜'Z')
+  A ← +´∘∾ {(Prio¨×∊⟜𝕩)𝕨}○⍷´∘(<˘ 2‿∘⊸⥊)¨
+  B ← +´∘∾ {a‿b‿c:(Prio¨a)×b∧○(a⊸∊)c}¨∘(3⊸Chunk)∘(⍷¨)
+  (A⋈B) •FLines 𝕩
+}
+# •Show Day3 ⊑•args