solved part 2

day10/solution2.rb

@@ -0,0 +1,36 @@
+#!/bin/env ruby
+require 'pry'
+numbers = File.read('./input').split("\n").map(&:to_i).sort
+numbers.prepend(0)
+numbers.push(numbers[-1] + 3)
+#binding.pry
+solution = numbers.map.with_index do |num, i|
+    next if i == 0
+    num - numbers[i-1]
+end
+solution.compact!
+count = [0]
+count_i = 0
+solution.each.with_index do |num, i|
+    next if i == 0
+    if num == 3
+        count_i += 1
+        count.push(0)
+        next
+    end
+    count[count_i] += 1 if solution[i-1] == 1
+end
+
+count.delete(0)
+count.map! do |num|
+    case num
+    when 1
+        2
+    when 2
+        4
+    when 3
+        7        
+    end
+end
+
+p count.reduce(:*)