aboutsummaryrefslogtreecommitdiffstats
path: root/AoC2023/day02/solver.lisp
diff options
context:
space:
mode:
Diffstat (limited to 'AoC2023/day02/solver.lisp')
-rw-r--r--AoC2023/day02/solver.lisp79
1 files changed, 79 insertions, 0 deletions
diff --git a/AoC2023/day02/solver.lisp b/AoC2023/day02/solver.lisp
new file mode 100644
index 0000000..60aa3cf
--- /dev/null
+++ b/AoC2023/day02/solver.lisp
@@ -0,0 +1,79 @@
+(ql:quickload '(uiop fiveam cl-ppcre))
+(defparameter eg-input "Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
+Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
+Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
+Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green")
+
+(defun parse-set (info)
+ (let (list)
+ (cl-ppcre:do-register-groups ((#'parse-integer count) (#'read-from-string color))
+ ("(\\d+) (blue|red|green)" info)
+ (push (list color count) list))
+ list))
+
+(defun in-limits (max-red max-green max-blue)
+ (lambda (value)
+ (destructuring-bind (color count) value
+ (<= count
+ (ecase color
+ (red max-red)
+ (green max-green)
+ (blue max-blue))))))
+
+(defun parse-game (game-bounds)
+ (lambda (line)
+ (destructuring-bind (game . sets)
+ (uiop:split-string line :separator '(#\; #\:))
+ (if (every
+ (lambda (s)
+ (every game-bounds (parse-set s)))
+ sets)
+ (parse-integer (cl-ppcre:scan-to-strings "\\d+" game))
+ 0))))
+
+(defun game-powers (line)
+ (apply #'* (mapcar #'cadr (parse-set (cdr (uiop:split-string line :separator '(#\; #\:)))))))
+
+(defun solve1 (lines bounds)
+ (reduce
+ #'+
+ lines
+ :key (parse-game bounds)))
+
+
+(defun max-set (top set)
+ (loop for (color count) in set do
+ (let ((var (ecase color
+ (red 0)
+ (green 1)
+ (blue 2))))
+ (setf (elt top var) (max (elt top var) count))))
+ top)
+
+(defun solve2 (lines)
+ (apply #'+
+ (mapcar (lambda (line)
+ (apply #'*
+ (reduce #'max-set (cdr (uiop:split-string line :separator '(#\; #\:)))
+ :key #'parse-set
+ :initial-value (make-list 3 :initial-element 0))))
+ lines)))
+
+(fiveam:test solutions
+ (fiveam:is
+ (= 8
+ (solve1
+ (uiop:split-string eg-input :separator '(#\Newline))
+ (in-limits 12 13 14))))
+ (fiveam:is
+ (= 2369
+ (solve1
+ (uiop:read-file-lines "input")
+ (in-limits 12 13 14))))
+ (fiveam:is
+ (= 2286
+ (solve2 (uiop:split-string eg-input :separator '(#\Newline)))))
+ (fiveam:is
+ (= 66363
+ (solve2 (uiop:read-file-lines "input")))))