From 2d7ab0c02098878ab78ed85a549cea1f32fa7986 Mon Sep 17 00:00:00 2001
From: Jay Foad <jay.foad@gmail.com>
Date: Fri, 7 Dec 2018 12:51:52 +0000
Subject: [PATCH] Day 6 part 2 super fast avoiding all outer products.

---
 p6linear.dyalog | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 p6linear.dyalog

diff --git a/p6linear.dyalog b/p6linear.dyalog
new file mode 100644
index 0000000..d23010b
--- /dev/null
+++ b/p6linear.dyalog
@@ -0,0 +1,4 @@
+p←↑⍎¨⊃⎕NGET'p6.txt'1
+sort←{(⊂⍋⍵)⌷⍵}
+f←{+\(+/⍵),¯1↓(-≢⍵)++\0,z⊣z[⍵]+←2⊣z←0/⍨⌈/⍵}
++/(sort f⊣/p)⍸9999-f⊢/p ⍝ part 2