#lang racket (require "../lib/utils.rkt") (require "../lib/obj.rkt") (define fp (open-input-file "input")) (define lines (get-lines fp)) (define (strip-head s) (string-trim (cadr (string-split s ":")))) (set! lines (map strip-head lines)) (define make-card (obj-maker 'win-nums 'nums)) (define (parse-card s) (define lst (string-split s "|")) (define win-nums (map string->number (string-split (car lst)))) (define nums (map string->number (string-split (cadr lst)))) (make-card win-nums nums)) (define (point card) (define wins (length (filter (λ (x) (member x (card 'win-nums))) (card 'nums)))) (if (= wins 0) 0 (expt 2 (- wins 1)))) (apply + (map point (map parse-card lines)))