Initial commit

2022/day03/day03.rkt

@@ -0,0 +1,28 @@
+#lang racket
+
+(define (read-input filename)
+  (map string->list (file->lines filename)))
+
+(define (score items)
+  (for/sum ([it items])
+    (cond
+     [(char-lower-case? it) (- (char->integer it) 96)]
+     [(char-upper-case? it) (+ 27 (- (char->integer it) 65))])))
+
+(define (part1 in)
+  (score
+    (for/list ([l in])
+      (define-values (a b) (split-at l (/ (length l) 2)))
+      (car (set-intersect a b)))))
+
+(define (part2 in)
+  (let lp ([l in]
+	   [res '()])
+    (match l
+      ['() (score res)]
+      [(list-rest a b c rest)
+       (lp rest (cons (car (set-intersect a b c)) res))])))
+
+(define in (read-input "input"))
+(displayln (part1 in))
+(displayln (part2 in))