segments_union.rb

def segmentsUnion(left, right)
   x = 1
   sum = 0
   left = left.sort
   right = right.sort
   sum = right[0] - left[0]

   while (x < left.length)
         if left[x] < right[x - 1] then
            sum = right[x] - left[0]
         else
            sum = sum + (right[x] - left[x])
         end

         x = x + 1
   end

   return sum

end