From 8777ff071f7bb37631baa7b6717ad29961e50911 Mon Sep 17 00:00:00 2001 From: "H.J" Date: Wed, 9 Oct 2024 11:36:55 -0400 Subject: sorting by language --- aoc2023-racket/day-09/day-09.rkt | 32 -------------------------------- 1 file changed, 32 deletions(-) delete mode 100644 aoc2023-racket/day-09/day-09.rkt (limited to 'aoc2023-racket/day-09/day-09.rkt') diff --git a/aoc2023-racket/day-09/day-09.rkt b/aoc2023-racket/day-09/day-09.rkt deleted file mode 100644 index 5eda1eb..0000000 --- a/aoc2023-racket/day-09/day-09.rkt +++ /dev/null @@ -1,32 +0,0 @@ -#lang racket - -(require advent-of-code - threading) - -(define histories - (for/list ([raw-history (in-lines (open-aoc-input (find-session) 2023 9 #:cache #true))]) - (~>> raw-history - string-split - (map string->number)))) - -(define (constant? xs) - (= 1 (length (remove-duplicates xs)))) - -(define/match (derivative xs) - [((list a b)) (list (- b a))] - [((list* a b _)) (cons (- b a) (derivative (rest xs)))]) - -(define (extrapolate xs) - (if (constant? xs) - (car xs) - (+ (last xs) (extrapolate (derivative xs))))) - -;; part 1 -(~>> histories - (map extrapolate) - (apply +)) - -;; part 2 -(~>> histories - (map (λ~> reverse extrapolate)) - (apply +)) -- cgit v1.2.3