From c433bf1344c0325907609f81c8554fc3d0bc2ecc Mon Sep 17 00:00:00 2001
From: Jay Foad <jay.foad@gmail.com>
Date: Wed, 2 Jan 2019 15:25:10 +0000
Subject: [PATCH] Day 20 solution.

---
 p20.dyalog | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 p20.dyalog

diff --git a/p20.dyalog b/p20.dyalog
new file mode 100644
index 0000000..86f3a11
--- /dev/null
+++ b/p20.dyalog
@@ -0,0 +1,6 @@
+p←1↓¯2↓⊃⎕NGET'p20.txt'
+r←s←1 2⍴0
+{⍵='(':s⍪←⊢⌿r ⋄ ⍵='|':r⍪←⊢⌿s ⋄ ⍵=')':s↓⍨←¯1 ⋄ r⍪←(⊢⌿r)+1,0J1*'NESW'⍳⍵}¨p
+t←⊃{⌊/⍵}⌸/⌽↓⍉r
+⌈/t ⍝ part 1
++/999<t ⍝ part 2