return to day 3 part 1, partial

day3.bqn

@@ -1,18 +1,6 @@
 #!/usr/bin/env cbqn
 
-# You (me) notice that no number is more than 3 digits long. Why not take a 
-# different approach:
-
-# 1. Find symbols in grid via "#$%&*+-/=@"
-# 2. Propagate symbols in a moore neighbourhood to digits
-# 3. Propagate twice more over any L-R digits
-# 4. Mask the grid
-# 5. Parse and sum
-
-# Written after finishing the final tutorial, and skimming the "Quick Start".
-# Understanding arrays might have have been really useful, but I guess I'm out
-# of luck as they seems to have really increased the difficulty this year to
-# combat LLMs.
+# Written after day 4, because of a logical error with the first attempt. 
 
 e1 ← ⟨
   "467..114.."
@@ -27,52 +15,54 @@ e1 ← ⟨
   ".664.598.."
 ⟩
 
-# Ah fuck. this idea is _wrong_
-# Game plan:
-#   Part 1: 
-#     Somehow "467..114.." -> ⟨467, 467, 467, 0, 0, 114, 114, 114, 0, 0⟩
-#   Part 2: 
-#     Identify non digit and non . as 1, others as 0
-#   Part 3:
-#     Propagate all 1s in the part 2 grid in a moore neighbourhood
-#   Part 4:
-#     Multiply part 3 on part 1 and sum
-
-# Part 1
-# Symbols used (from ∧⍷∾ on input): #$%&*+-/=@ . 0123456789
-symbols ← "#$%&*+-/=@"
-# Not very idomatic ;(
+# From BQNcreate: Pad with a layer of fill elements on all sides
+Pad ← (⊢↑˝·≍⟜¬2+≢)
+
+GetSymbols ← {¬".0123456789"∊˜𝕩}⊸/⍷∘∾
+symbols ← Pad (GetSymbols e1) ∊˜ >e1
 IsDigit ← {('0' ≤ 𝕩) ∧ (𝕩 ≤ '9')}
-# From BQNCrate: Split 𝕩 at occurrences of separators 𝕨, removing the separators
-SplitSep ← {𝕨 ((⊢-˜¬×·+`»⊸<)∘∊˜⊔⊢) 𝕩}
-LineNumbers ← •parseFloat¨ ({0≠≠¨𝕩}⊸/('.'∾symbols)⊸SplitSep)
-NumberIndex1 ← {
-  mask ← IsDigit 𝕩
-  # sum reduce over the falling edge
-  # add 1 to distinguish between 0s
-  mask × 1+ +` (»mask) ∧ ¬mask
+digits ← Pad (IsDigit×-⟜'0') >e1 
+
+# We need to pad these because Grow wraps the grid
+parsed ← symbols ⋈¨ digits
+
+# Adapted from BQNcrate GoL to just sum the neighbours to 1 step propogate symbols
+Grow ← {0<⊑+˝⥊⌽⟜𝕩¨⋈⌜˜¯1‿0‿1}
+# Cull symbols where digits is 0, padding is always culled
+Cull ← {
+  s‿d ← 𝕩
+  (0≠s×d)‿d
+} 
+# Spread symbols left and right
+Spead ← {
+  s ← ⊑¨ 𝕩
+  neighbourhood ← ⌽⟜s¨⋈⌜˜¯1‿0‿1
+  spread ← ⊑0<+˝˘ 1↑1↓ neighbourhood
+  spread ⋈ ¨ 1⊑¨ 𝕩
 }
-Part1 ← {⊑⟜(0∾(LineNumbers 𝕩))¨ (NumberIndex1 𝕩)}
-
-# Part 2
-
-GetSymbols ← >{∨´𝕩⍷symbols}¨¨
-
-# Part 3
-# Butchered from GoL found on BQNcrate
-Propagate ← {⊑1=+˝⥊⌽⟜𝕩¨⋈⌜˜¯1‿0‿1} 
+Harvest ← {
+  s‿d ← 𝕩
+  d ×⟜s ↩
+  (d > 0)⊑'.'‿('0'+d)
+} 
 
-(>Part1¨ e1) × (Propagate∘GetSymbols e1)
+# Adapted BQNCrate split for digits only
+SplitDigits ← {((⊢-˜¬×·+`»⊸<)∘¬∘IsDigit˜⊔⊢) 𝕩}
+MaxDigitLen ← {⌈´ ≠¨ ∾ SplitDigits¨ 𝕩}
 
+init ← Cull¨ Grow ⌾ (⊑¨) parsed
+# If we grew into a digit, we need to spread until we reach the entire number
+h ← Harvest¨ Cull¨∘Spead⍟(1-˜MaxDigitLen e1) init
 
+# WIP, now to unravel and parse as floats
 
 
 
 
 
 # Thoughts:
 
-# The quick start really shows off a lot more BQN that I ever thought existed!
+# The Quick Start really shows off a lot more BQN that I ever thought existed!
 # There's syntax to do pseudo-procedural programming! I wonder how much overlap
 # there is with other array languages.
 
@@ -87,6 +77,5 @@ Propagate ← {⊑1=+˝⥊⌽⟜𝕩¨⋈⌜˜¯1‿0‿1}
 # I can try moving to local development.
 
 input ← •FLines "inputs/day3.txt"
-•Show ⟨"Symbols: ", ∧⍷∾ input⟩
 # •Show ⟨"Part 1", input⟩ 
 # •Show ⟨"Part 2", input⟩