From 3d518b0b0568c2013dd5eb35ab87a7431433d5a9 Mon Sep 17 00:00:00 2001
From: Ben Harris <bjh21@bjh21.me.uk>
Date: Sun, 5 May 2024 12:32:25 +0100
Subject: [PATCH] Tidy up and comment map prep in 05a

---
 05/05a.bqn | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/05/05a.bqn b/05/05a.bqn
index f144cf1..7990c6b 100644
--- a/05/05a.bqn
+++ b/05/05a.bqn
@@ -13,10 +13,11 @@ Prep1Proc←{ # Prepare one step of procedure
 
 Prep←{
   ⟨rawmap, rawproc⟩←(""⊸≡¨𝕩)Split𝕩
-  map0←{(𝕩≠' ')/𝕩}¨<˘⍉⌽>¯1↓rawmap
-  map1←⟨""⟩∾(1=4|↕≠map0)/map0
+  map0←⍉>¯1↓rawmap            # Drop last line and transpose
+  map1←(1=4|↕≠map0)/map0      # Extract crate letters from chaff
+  map←⟨""⟩∾{(𝕩≠' ')/𝕩}¨<˘map1 # Convert to a 0-based list of strings
   proc←∾Prep1Proc¨rawproc
-  ⟨map1, proc⟩
+  ⟨map, proc⟩
 }
 
 •Show Prep •file.Lines ⊑•args
-- 
2.30.2