Snake Case Challenge

SNAKE.md

Snake Case Challenge

$ time ruby snake_case.rb
184756
ruby snake_case.rb  0.05s user 0.01s system 94% cpu 0.061 total

snake_case.rb

Grid = Struct.new(:n, :m) do
  # Finds the number of ways `n` and `m` positions
  # we can choose from `n * m` available paths
  def unique_paths
    factorial(self.n + self.m)/(factorial(self.n) * factorial(self.m))
  end

  private

  def factorial(n)
    (1..n).inject(:*)
  end
end

puts Grid.new(10, 10).unique_paths