From d6aa267e8e03dde70b59e262bb2aacdf3d071ec9 Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Tue, 1 Dec 2020 21:13:43 -0800
Subject: [PATCH] Add day2 solution.

---
 day2.cr | 41 ++++++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 19 deletions(-)

diff --git a/day2.cr b/day2.cr
index 83986bd..5020481 100644
--- a/day2.cr
+++ b/day2.cr
@@ -1,17 +1,23 @@
 INPUT = File.read("day2.txt").lines.map(&.chomp) 
 
+def parse(line)
+    data = line.match(/([0-9]+)-([0-9]+) ([a-z]): ([a-z]+)/) 
+    data.try do |data|
+      min = data[1].to_i
+      max = data[2].to_i
+      char = data[3][0]
+      str = data[4]
+      {min,max,char,str}
+    end
+end
+
 def part1
   input = INPUT.clone
-  total = 0
-  input.each do |line|
-    data = line.match(/([0-9]+)-([0-9]+) ([a-z]): ([a-z]+)/) 
-    next unless data
-    min = data[1].to_i
-    max = data[2].to_i
-    char = data[3][0]
-    str = data[4]
+  total = input.count do |line|
+    next false unless data = parse(line)
+    min, max, char, str = data
     count = str.chars.count(char)
-    total += 1 if count >= min && count <= max
+    count >= min && count <= max
   end
 
   puts total
@@ -19,17 +25,14 @@ end
 
 def part2
   input = INPUT.clone
-  total = 0
-  input.each do |line|
-    data = line.match(/([0-9]+)-([0-9]+) ([a-z]): ([a-z]+)/) 
-    next unless data
-    min = data[1].to_i - 1
-    max = data[2].to_i - 1
-    char = data[3][0]
-    str = data[4]
-    count = str.chars.count(char)
-    total += 1 if ((str[min] == char) || (str[max] == char) ) && str[min] != str[max]
+  total = input.count do |line|
+    next false unless data = parse(line)
+    min, max, char, str = data
+    min -= 1
+    max -= 1
+    ((str[min] == char) || (str[max] == char) ) && str[min] != str[max]
   end
+
   puts total
 end