45 lines
1.1 KiB
Racket
45 lines
1.1 KiB
Racket
|
#lang curly-fn racket
|
||
|
|
|
||
|
|
(require "scripts/aoc.rkt")
|
||
|
|
|
||
|
|
;; solution for day 9
|
||
|
|
|
||
|
|
;; helper functions here
|
||
|
|
|
||
|
|
(define (part1 input)
|
||
|
|
(define vec (list->vector input))
|
||
|
|
(let/ec exit
|
||
|
|
(for ([i (in-range 25 (vector-length vec))])
|
||
|
|
(define valid?
|
||
|
|
(for*/first ([a (in-range (- i 25) i)] [b (in-range a i)]
|
||
|
|
#:when (= (vector-ref vec i) (+ (vector-ref vec a) (vector-ref vec b)))) #t))
|
||
|
|
(unless valid?
|
||
|
|
(exit (vector-ref vec i))))))
|
||
|
|
|
||
|
|
(define (part2 input)
|
||
|
|
(define pt1 10884537)
|
||
|
|
(define pt1-i 501)
|
||
|
|
(let/ec exit
|
||
|
|
(define vec (list->vector input))
|
||
|
|
(define (cb args)
|
||
|
|
(when (= pt1 (apply + args))
|
||
|
|
(exit (+ (apply min args) (apply max args)))))
|
||
|
|
(for* ([ct (in-range 3 100)] [i (in-range 0 (- pt1-i ct))])
|
||
|
|
(define sub (vector-copy vec i (+ i ct)))
|
||
|
|
(cb (vector->list sub)))))
|
||
|
|
|
||
|
|
(module+ test
|
||
|
|
(require rackunit)
|
||
|
|
;; tests here
|
||
|
|
(displayln "no tests :("))
|
||
|
|
|
||
|
|
(module+ main
|
||
|
|
(define input (file->list "inputs/9"))
|
||
|
|
;; part 1
|
||
|
|
(answer 9 1 (part1 input))
|
||
|
|
|
||
|
|
;; part 2
|
||
|
|
(answer 9 2 (part2 input))
|
||
|
|
|
||
|
|
(displayln "meow"))
|