january adventing... omg...

1 files changed, 16 insertions, 0 deletions

diff --git a/2024/racket/day01.rkt b/2024/racket/day01.rkt
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+#lang racket
+
+;; Day 1: Historian Hysteria
+
+(command-line #:args (filename)
+(let* ([input (file->lines filename)]
+       [l1 (map (λ (x) (string->number (substring x 0 5))) input)]
+       [l2 (map (λ (x) (string->number (substring x 8 13))) input)])
+
+(foldl
+  (λ (a b acc) (+ acc (abs (- a b))))
+  0 (sort l1 <) (sort l2 <))
+
+(foldl
+  (λ (a acc) (+ acc (* a (count (λ (x) (= x a)) l2))))
+  0 l1)))