ruby_code_solutions

ruby_code_solutions.rb

###############
## Factorial ##
###############
# 1:
def fac1 n
  v = 1
  (1..n).each {|t| v *= t}
  v
end

# 2:
def fac2 n
  (1..n).inject(1) {|s, i| s *= i }
end

# 3:
def fac3 n
  return 1 if n == 1
  n*fac3(n-1)
end

# 4:
class Integer 
  def fac
    return self if self == 1
    self*(self-1).fac
  end
end
[1,2,3,4,5].map(&:fac) #  [1, 2, 6, 24, 120]