1 files changed, 30 insertions, 0 deletions
diff --git a/2021/day-16/day-16.rkt b/2021/day-16/day-16.rkt
new file mode 100644
index 0000000..80c2a54
--- /dev/null
+++ b/2021/day-16/day-16.rkt
@@ -0,0 +1,30 @@
+#lang racket
+(require "../../jj-aoc.rkt"
+         threading)
+
+(define data
+  (~> (open-day 16 2021)
+      port->string
+      string-trim
+      string->list))
+
+(define (hex->bin h)
+  (match h
+    [#\0 '(0 0 0 0)]
+    [#\1 '(0 0 0 1)]
+    [#\2 '(0 0 1 0)]
+    [#\3 '(0 0 1 1)]
+    [#\4 '(0 1 0 0)]
+    [#\5 '(0 1 0 1)]
+    [#\6 '(0 1 1 0)]
+    [#\7 '(0 1 1 1)]
+    [#\8 '(1 0 0 0)]
+    [#\9 '(1 0 0 1)]
+    [#\A '(1 0 1 0)]
+    [#\B '(1 0 1 1)]
+    [#\C '(1 1 0 0)]
+    [#\D '(1 1 0 1)]
+    [#\E '(1 1 1 0)]
+    [#\F '(1 1 1 1)]))
+
+(map hex->bin data)
+\ No newline at end of file