added a very good (or very bad) implementation of day 6.

src/advent/day6.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+def get_critical_points(time, record)
+  delta = Math.sqrt(time*time - 4 * record)
+  epsilon = 0.000000000001 # math is not life
+  [(time - delta)/2, (time + delta)/2 - epsilon]
+end
+
+def number_of_possible_way_to_beat_the_record(time, record)
+  critical_points = get_critical_points(time, record)
+  critical_points[1].floor - critical_points[0].floor
+end
+
+
+inputs = [[56, 334], [71, 1135], [79, 1350], [99, 2430]]
+part_1 = inputs.map { |x| number_of_possible_way_to_beat_the_record x[0], x[1] }
+      .reduce 1, :*
+
+puts "Part 1: #{part_1}"
+
+
+part_2 = number_of_possible_way_to_beat_the_record 56717999,  334113513502430
+
+puts "Part 2: #{part_2}"
+
+

src/advent/day_6_input.txt

@@ -0,0 +1,2 @@
+Time:        56     71     79     99
+Distance:   334   1135   1350   2430