feat(sterni/aoc/2021): day 1 solution r/3128

Change-Id: I0781b2aa3624df9a3158296edcbbbf2ee845102b

2 files changed, 32 insertions, 0 deletions

diff --git a/users/sterni/exercises/aoc/.gitignore b/users/sterni/exercises/aoc/.gitignore
new file mode 100644
index 000000000000..de53cfc531cb
--- /dev/null
+++ b/users/sterni/exercises/aoc/.gitignore
@@ -0,0 +1 @@
+/*/input
\ No newline at end of file
diff --git a/users/sterni/exercises/aoc/2021/solutions.bqn b/users/sterni/exercises/aoc/2021/solutions.bqn
new file mode 100755
index 000000000000..98d70f8f15cf
--- /dev/null
+++ b/users/sterni/exercises/aoc/2021/solutions.bqn
@@ -0,0 +1,31 @@
+#!/usr/bin/env BQN
+
+#
+# Utilities
+#
+
+ReadInt ← (10⊸×+⊣)´∘⌽-⟜'0' # stolen from leah2
+
+ReadInput ← {ReadInt¨•file.Lines ∾ •path‿"/input/day"‿(•Fmt 𝕩)}
+
+#
+# 2021-12-01
+#
+
+# part 1
+
+day1ExampleData ← 199‿200‿208‿210‿200‿207‿240‿269‿260‿263
+
+# NB: Because distance from the ground is never smaller than zero, it's
+# no problem that nudge inserts a zero at the end of the right list
+PositiveDeltaCount ← +´∘(⊢<«)+˝˘∘↕
+
+! 7 = 1 PositiveDeltaCount day1ExampleData
+
+•Out "Day 1.1: "∾•Fmt 1 PositiveDeltaCount ReadInput 1
+
+# part 2
+
+! 5 = 3 PositiveDeltaCount day1ExampleData
+
+•Out "Day 1.2: "∾•Fmt 3 PositiveDeltaCount ReadInput 1