From 08e588c7e3ec7606ddd66a968c6aa586b54edf69 Mon Sep 17 00:00:00 2001
From: Oscar Najera <hi@oscarnajera.com>
Date: Fri, 2 Dec 2022 18:22:22 +0100
Subject: [AoC2022] 02 doing it in Common lisp

---
 AoC2022/02/solver.lisp | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 AoC2022/02/solver.lisp

(limited to 'AoC2022/02/solver.lisp')

diff --git a/AoC2022/02/solver.lisp b/AoC2022/02/solver.lisp
new file mode 100644
index 0000000..58abd1b
--- /dev/null
+++ b/AoC2022/02/solver.lisp
@@ -0,0 +1,56 @@
+(ql:quickload :fiveam)
+
+(defconstant results '((rock . scissors) (scissors . paper) (paper . rock))
+  "Win-lose pairs")
+
+(defun translate (play)
+  (case play
+    ((A X) 'rock)
+    ((B Y) 'paper)
+    ((C Z) 'scissors)))
+
+(defun weight (play)
+  (case play
+    (rock 1)
+    (paper 2)
+    (scissors 3)))
+
+(defun match (my other)
+  (cond
+    ((eq my other) (values 3 'draw))
+    ((eq other (cdr (assoc my results))) (values 6 'win))
+    (t (values 0 'loose))))
+
+(defun strategy (play)
+  (ecase play
+      (X 'loose)
+      (Y 'draw)
+      (Z 'win)))
+
+(defun pick-move (strategy other)
+  (ecase strategy
+    (loose (cdr (assoc other results)))
+    (draw other)
+    (win (car (rassoc other results)))))
+
+(defun fixed-plays (oponent my)
+  (declare (ignore oponent))
+  (translate my))
+
+(defun reactive-plays (oponent my)
+  (pick-move (strategy my) oponent))
+
+(defun solver (strategy)
+  (with-open-file (in "input")
+    (loop :for n :from 0
+          :for op = (translate (read in nil nil))
+          :while op
+          :for my = (funcall strategy op (read in nil nil))
+          :sum (+ (weight my) (match my op)))))
+
+(fiveam:test results
+  (fiveam:is (= 12535 (solver #'fixed-plays)))
+  (fiveam:is (= 15457 (solver #'reactive-plays))))
+
+
+(fiveam:run-all-tests)
-- 
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