From 3bed3ac4af62370aeb10fab7f962f5eb3b2eadc5 Mon Sep 17 00:00:00 2001
From: Jay Foad <jay.foad@gmail.com>
Date: Tue, 11 Dec 2018 15:17:00 +0000
Subject: [PATCH] Day 11 shorter and faster with n-wise reduction.

---
 p11nwise.dyalog | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 p11nwise.dyalog

diff --git a/p11nwise.dyalog b/p11nwise.dyalog
new file mode 100644
index 0000000..7127af9
--- /dev/null
+++ b/p11nwise.dyalog
@@ -0,0 +1,5 @@
+⎕IO←1
+p←⍎⊃⊃⎕NGET'p11.txt'1
+g←{r y←10 0+⍵ ⋄ ¯5+10|⌊100÷⍨r×p+y×r}¨⍳300 300 ⍝ grid
+⊃⍸{⍵=⌈/,⍵}3+/3+⌿g ⍝ part 1
+1↓{(⊃⍒⍵)⌷⍵}↑1{0>m←⌈/,t←⍺+/⍺+⌿g:⍵ ⋄ (⍺+1)∇⍵,⊂m,(⊃⍸m=t),⍺}⍬ ⍝ part 2