From 00e8704ac3cdf70ebfa1bb8e463b1e32d749c14e Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Wed, 2 Dec 2020 21:14:34 -0800
Subject: [PATCH] Add day3 solution.

---
 day3.cr | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 day3.cr

diff --git a/day3.cr b/day3.cr
new file mode 100644
index 0000000..f1c6fa2
--- /dev/null
+++ b/day3.cr
@@ -0,0 +1,29 @@
+INPUT = File.read("day3.txt").lines.map(&.chomp) 
+
+def run(input, slopes)
+  prod = 1_i64
+  slopes.each do |slope|
+    trees = 0
+    pos = 0
+    line = 0
+    right, down = slope
+    while line < input.size
+      trees += 1 if input[line][pos] == '#'
+      pos = (pos + right) % input[line].size
+      line += down
+    end
+    prod *= trees
+  end
+  prod
+end
+
+def part1
+  puts run(INPUT, [{3,1}])
+end
+
+def part2
+  puts run(INPUT, [{1,1}, {3,1}, {5,1}, {7,1}, {1,2}])
+end
+
+part1
+part2