Kazinator's Advent of Code stuff.

1 files changed, 42 insertions, 0 deletions

diff --git a/2021/08/two.tl b/2021/08/two.tl
new file mode 100644
index 0000000..f436779
--- /dev/null
+++ b/2021/08/two.tl
@@ -0,0 +1,42 @@
+(defstruct entry ()
+  digs
+  value)
+
+(defun read-input (: (name "input"))
+  (flet ((str-to-syms (str)
+           (flow str
+             (spl " ")
+             (mapcar (opip (tuples 1)
+                           (mapcar intern-fb))))))
+    (flow
+      (file-get-lines name)
+      (mapcar (do match `@a | @b` @1
+                (new entry
+                     digs (str-to-syms a)
+                     value (str-to-syms b)))))))
+
+(defun match-dig (syms)
+  (match-case syms
+    ((a b c e f g)   0)
+    ((c f)           1)
+    ((a c d e g)     2)
+    ((a c d f g)     3)
+    ((b c d f)       4)
+    ((a b d f g)     5)
+    ((a b d e f g)   6)
+    ((a c f)         7)
+    ((a b c d e f g) 8)
+    ((a b c d f g)   9)))
+
+(defmeth entry solve (e)
+  (each ((p (perm '(a b c d e f g))))
+    (let* ((map (relate '(a b c d e f g) p))
+           (interp (mapcar (opip (mapcar map) sort) e.digs))
+           (digs (remq nil [mapcar match-dig interp])))
+      (if (eql 10 (len digs))
+        (return (flow e.value
+                  (mapcar (opip (mapcar map) sort match-dig))
+                  (poly 10)))))))
+
+(defun solve (input)
+  (sum input .(solve)))