From 8777ff071f7bb37631baa7b6717ad29961e50911 Mon Sep 17 00:00:00 2001
From: "H.J" <thechairman@thechairman.info>
Date: Wed, 9 Oct 2024 11:36:55 -0400
Subject: sorting by language

---
 racket/aoc2020/day-03/day-03.rkt | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 racket/aoc2020/day-03/day-03.rkt

(limited to 'racket/aoc2020/day-03/day-03.rkt')

diff --git a/racket/aoc2020/day-03/day-03.rkt b/racket/aoc2020/day-03/day-03.rkt
new file mode 100644
index 0000000..ee9edcf
--- /dev/null
+++ b/racket/aoc2020/day-03/day-03.rkt
@@ -0,0 +1,16 @@
+#lang racket
+(require "../../jj-aoc.rkt"
+         threading)
+
+(define (check-for-trees run rise)
+  (for*/sum ([(row i) (in-indexed (port->lines (open-day 3 2020)))]
+             #:when (= 0 (modulo i rise))
+             [possible-tree (in-value (sequence-ref (in-cycle row) (* (/ run rise) i)))]
+             #:when (and (char=? possible-tree #\#)))
+            1))
+
+;; part 1
+(check-for-trees 3 1)
+
+;; part 2
+(~>> '((1 1) (3 1) (5 1) (7 1) (1 2)) (map (curry apply check-for-trees)) (apply *))
-- 
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