Fibonacci sequence with and without recursion.

fibonacci.rb

# Fibonacci sequence with and without recursion

def fibs(num) # Not recursive
	return num if num <= 1
	
	fib = 1
	fib_prev = 1
	count = 2
	
	while count < num
	    count += 1
	    temp = fib
	    fib += fib_prev
	    fib_prev = temp
	end
	
	return fib
end

def fibs_rec(num) # Recursive
	return num if num <= 1
	fib_rec(num - 1) + fib_rec(num - 2)
end

# EXAMPLES
puts fibs(0) # => 0
puts fibs(5) # => 5
puts fibs_rec(1) # => 1
puts fibs_rec(10) # => 55