Initial commit

2020/day06/day06.rkt

@@ -0,0 +1,37 @@
+#lang racket
+
+(module+ test
+  (require rackunit))
+
+(module+ main
+  (displayln "Day 6"))
+
+(define (read-input filename)
+  (string-split (file->string filename) "\n\n"))
+
+(define (count-unique str)
+  (set-count (set-remove (list->set (string->list str)) #\newline)))
+
+(define (part1 filename)
+  (apply + (map count-unique (read-input filename))))
+
+(module+ test
+  (check-equal? (part1 "test") 11))
+
+(module+ main
+  (displayln (part1 "input")))
+
+(define (count-intersection str)
+  (define answers (string-split str "\n"))
+  (set-count
+   (apply set-intersect
+          (map (compose list->set string->list) answers))))
+
+(define (part2 filename)
+  (apply + (map count-intersection (read-input filename))))
+
+(module+ test
+  (check-equal? (part2 "test") 6))
+
+(module+ main
+  (displayln (part2 "input")))