2022 day 6 part 1

Author: Robb Kidd

2022/ruby/day06.rb

@@ -0,0 +1,56 @@
+class Day06
+  def self.go
+    day = new
+    puts "Part 1: #{day.part1}"
+    puts "Part 2: #{day.part2}"
+  end
+
+  def initialize(input=nil)
+    @input = input || real_input
+  end
+
+  def part1
+    start_of_packet_marker(@input)
+  end
+
+  def part2
+  end
+
+  # @example
+  #   day.start_of_packet_marker('mjqjpqmgbljsphdztnvjfqwrcgsmlb') => 7
+  #   
+  # @example
+  #   day.start_of_packet_marker('bvwbjplbgvbhsrlpgdmjqwftvncz') => 5
+  #   
+  # @example
+  #   day.start_of_packet_marker('nppdvjthqldpwncqszvftbrmjlhg') => 6
+  #   
+  # @example
+  #   day.start_of_packet_marker('nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg') => 10
+  #   
+  # @example
+  #   day.start_of_packet_marker('zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw') => 11
+  #   
+  def start_of_packet_marker(buffer)
+    chars = buffer.tr("\n","").chars
+    scan = 3
+    found = false
+    while !found || scan < chars.length do
+      check = chars[scan-3..scan]
+      if check.uniq.length == 4
+         found = true
+         break
+      end
+      scan += 1
+    end
+    return scan + 1
+  end
+
+  def real_input
+    File.read('../inputs/day06-input.txt')
+  end
+
+  EXAMPLE_INPUT = <<~INPUT
+    mjqjpqmgbljsphdztnvjfqwrcgsmlb
+  INPUT
+end