From 8ab65dc2da1742eb86ec636c50c7018385b68167 Mon Sep 17 00:00:00 2001
From: "J.J" <thechairman@thechairman.info>
Date: Thu, 30 Nov 2023 17:10:00 -0500
Subject: prep for 2023, renaming for consistency

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

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

diff --git a/aoc2020/day-03/day-03.rkt b/aoc2020/day-03/day-03.rkt
new file mode 100644
index 0000000..ee9edcf
--- /dev/null
+++ b/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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