[p11] Part 1 and 2 done

p11/p11.org

@@ -0,0 +1,47 @@
+#+title: solution to p11
+
+#+begin_src emacs-lisp :results none
+  (with-temp-buffer
+    (insert-file-contents "input")
+    (advent/replace-multiple-regex-buffer
+     '((":" . " ")
+       ("^" . "(")
+       ("$" . ")")))
+    (goto-char (point-min))
+    (insert "(setq data '(")
+    (goto-char (point-max))
+    (insert "))")
+    (eval-buffer))
+#+end_src
+
+This is for part 1
+#+begin_src emacs-lisp
+  (defun paths-from (label)
+    (if (eq label 'out) 1
+      (-sum (-map 'paths-from (cdr (assq label data))))))
+  (memoize 'paths-from)
+  (paths-from 'you)
+#+end_src
+
+#+RESULTS:
+: 701
+
+And this for part 2; note that there are no paths from dac to fft
+(there can be only paths in one direction, otherwise we would get
+a loop.
+#+begin_src emacs-lisp
+    (defun paths-from-to (label exit)
+      (if (eq label exit) 1
+        (if (eq label 'out) 0
+        (-sum (--map (paths-from-to it exit) (cdr (assq label data)))))))
+    (memoize 'paths-from-to)
+(* (paths-from-to 'svr 'fft)
+   (paths-from-to 'fft 'dac)
+   (paths-from 'dac))
+#+end_src
+
+#+RESULTS:
+: 390108778818526
+
+
+