From 0242a39a0659833610559504049811801b9f1b22 Mon Sep 17 00:00:00 2001
From: Jacopo De Simoi <wilderjds@protonmail.com>
Date: Thu, 18 Sep 2025 22:27:53 -0400
Subject: [PATCH] progress in part2

---
 p21/p21.org | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/p21/p21.org b/p21/p21.org
index b2e5311..1c5dd6f 100644
--- a/p21/p21.org
+++ b/p21/p21.org
@@ -149,7 +149,7 @@ would blow in my face since we would have too many options to check.
 #+end_src
 
 #+RESULTS:
-: 222670
+: 1972
 
 
 The new idea would be to run things bottom-down. For a given pair of
@@ -161,6 +161,17 @@ So we start from all possible combinations of keypad pairs
 #+begin_src emacs-lisp
   (setq direction-pairs  (let ((directions (advent/split-string-into-char-list "<>^vA")))
                            (-mapcat (lambda (x) (--map (cons x it) directions)) directions)))
+  (setq basis-induction
+   (--map (cons it (connecting-paths (char-pairs-to-coordinate-pairs it dir-keypad-data) dir-keypad-data)) direction-pairs)
+   first-step (--map (cons (car it) (pick-shortest-string (cdr it))) basis-induction) )
+
+  (defun iterate-robot (s al)
+    (apply #'concat (--map (cdr (assoc it al)) (split-into-char-pairs (concat "A" s)))))
+
+  (defun iterate-step (l)
+   (--map (cons (car it) (pick-shortest-string
+  			(--map (iterate-robot it l) (cdr it))))
+  	basis-induction)
+   )
 
-  (--map (connecting-paths (char-pairs-to-coordinate-pairs it dir-keypad-data) dir-keypad-data) direction-pairs)
 #+end_src