From 1b3ba7cbcb3448824c51bf58e8406814ee18e9c4 Mon Sep 17 00:00:00 2001
From: 4903000 <4903000@chiru.no>
Date: Mon, 7 Dec 2020 23:48:16 +0000
Subject: [PATCH] Day 7

Almost done
---
 aoc20.lisp | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/aoc20.lisp b/aoc20.lisp
index 50bc648..bf3cc9d 100644
--- a/aoc20.lisp
+++ b/aoc20.lisp
@@ -248,3 +248,67 @@
   (let ((data (read-6 file)))
     (time (progn (print (solve-6-1 data))
 		 (print (solve-6-2 data))))))
+
+;;; day 7
+
+(defun read-bag (line)
+  (let ((key-bound (search "bags" line)))
+    (list (subseq line 0  (1- key-bound))
+	  (map 'list (lambda (r)
+		       (multiple-value-bind (n index) (parse-integer r :junk-allowed t)
+			 (unless (search "no other" r)
+			   (list (subseq r  (1+ index) (1- (search "bag" r))) n))))
+	       (split-sequence:split-sequence
+		#\, (subseq line (+ 1 (length "bags contain") key-bound)))))))
+
+(defun read-7 (file)
+  (with-open-file (stream file)
+    (loop for line = (read-line stream nil)
+	  while line
+	  collect (read-bag line))))
+
+(defun get-bag-symbols (data)
+  (map 'list (lambda (entry) (intern (first entry))) data))
+
+(defun build-graph (data)
+  (let ((symbols (get-bag-symbols data)))
+    (map 'list (lambda (entry)
+		 (set  (intern (first entry))
+		       (if (null (first (second entry)))
+			   nil
+			   (map 'list (lambda (r) (cons (intern (first r)) (second r)))
+				(second entry)))))
+	 (copy-seq data))))
+
+(defun recursive-search (node symbol)
+  (cond ((eq node nil)
+	 nil)
+	((member symbol (map 'list #'car node))
+	 t)
+	(t (or (recursive-search (eval (caar node)) symbol)
+	       (recursive-search  (cdr node) symbol)))))
+
+(defun solve-7-1 (data)
+  (length
+   (remove-if
+    #'null
+    (map 'list (lambda (sym)
+		 (recursive-search (eval sym) '|shiny gold|))
+	 (get-bag-symbols data)))))
+
+(defun count-bags (node &optional cheat)
+  (let* ((node (if (symbolp node) (eval node) node))
+	 (bag-multiplier-up (or (cdar node) 0))
+	 (bag-multiplier-right (or (cdadr node) 0))
+	 (bags-up (caar node))
+	 (bags-right (cdr node)))
+    (format t "m-up: ~A m-right: ~A node: ~A~%" bag-multiplier-up bag-multiplier-right node)
+    (cond (cheat 1)
+	  ((null node)
+	   0)
+	  ((not (null (eval (caar node))))
+	   (+ (* bag-multiplier-up (count-bags bags-up))
+	      (count-bags bags-right)
+	      bag-multiplier-up))
+	  (t (+ (* bag-multiplier-up (count-bags bags-up (if (null (eval (caar node))) t)))
+	        (count-bags bags-right))))))