add day 2 solutions

1 files changed, 38 insertions, 0 deletions

diff --git a/2-2.scm b/2-2.scm
new file mode 100755
index 0000000..240d8d1
--- /dev/null
+++ b/2-2.scm
@@ -0,0 +1,38 @@
+#!/usr/bin/env -S guile -s
+!#
+(use-modules (ice-9 regex)
+             (ice-9 textual-ports)
+             (srfi srfi-1))
+
+(define red-max 12)
+(define green-max 13)
+(define blue-max 14)
+
+(define (read-lines port)
+  (letrec ((loop (lambda (l ls)
+                   (if (eof-object? l)
+                       ls
+                       (loop (get-line port) (cons l ls))))))
+    (reverse (loop (get-line port) '()))))
+
+(define (triplet-values triplet)
+  (let* ((zero (string-match "(.)" "0"))
+         (red (string->number (match:substring (or (string-match "([0-9]+) red" triplet) zero) 1)))
+         (green (string->number (match:substring (or (string-match "([0-9]+) green" triplet) zero) 1)))
+         (blue (string->number (match:substring (or (string-match "([0-9]+) blue" triplet) zero) 1))))
+    `(,red ,green ,blue)))
+
+(define (line-value line)
+  (let* ((id-split (string-match "^Game ([0-9]+):(.*)$" line))
+         (rest (string-split (match:substring id-split 2) #\;))
+         (values (map triplet-values rest))
+         (red-min (fold (lambda (x y) (if (> x y) x y)) 0 (map car values)))
+         (green-min (fold (lambda (x y) (if (> x y) x y)) 0 (map cadr values)))
+         (blue-min (fold (lambda (x y) (if (> x y) x y)) 0 (map caddr values)))
+         (power (* red-min green-min blue-min)))
+    power))
+
+(let* ((port (open-input-file "2.txt"))
+       (lines (read-lines port)))
+  (close-port port)
+  (display (fold + 0 (map line-value lines))))