Initial commit

2017/01/day1.scm

@@ -0,0 +1,19 @@
+#!/usr/bin/csi -script
+
+(use extras)
+(use srfi-1)
+(use list-comprehensions)
+
+(define (sum-matching-offset k xs)
+  (let* ((n (length xs))
+	 (newxs (zip xs (take (drop (concatenate ((repeat 3) xs)) k) n)))
+	 (f (lambda (x acc) (if (= (first x) (second x)) (+ acc (first x)) acc))))
+    (foldr f 0 newxs)))
+
+(define (main)
+  (let* ((digits-str (read-line))
+	 (digits (map string->number (map string (string->list digits-str)))))
+    (print (sum-matching-offset 1  digits))
+    (print (sum-matching-offset (/ (length digits) 2) digits))))
+
+(main)