factorial.rb

def factorial(count)
  fact = 0 
  if count >= 0
    fact = (factorial(count-1))*count
  end 

  if count == 0
    fact = 1 
  end 
 fact
end

input1 = Integer(ARGV[0]) #N
input2 = Integer(ARGV[1]) #R


#excuse my shitty ruby por favor
print "FACTORIAL OF "
print input1
print " IS "
puts factorial(input1)

print "COMBINATION OF "
print input1
print " choose "
print input2
print " is: "
nfac = factorial(input1)
rfac = factorial(input2)

bottom = rfac * factorial(input1-input2)

combinations = nfac / bottom
puts combinations

print "PERMUTATION OF "
print input1
print " choose "
print input2
print " is: "
permutation = nfac / factorial(input1-input2)
puts permutation