benchmark fibonacci sequence recursive vs iterative

fibonacci_recursive_iterative.rb

require 'benchmark'

print "Recursive:\n"

def fibonacci(num)
  num < 2 ? num : fibonacci(num-1) + fibonacci(num-2)
end
 
puts Benchmark.measure { 200.times { fibonacci(20) } }

print "\nIterative:\n"

def fib(num)
  curr = 0
  succ = 1
  num.times { |n| curr, succ = succ, curr + succ }
  curr
end

puts Benchmark.measure { 200.times { fib(20) } }


#--------------------Output--------------------#

# Recursive:
#   0.810000   0.000000   0.810000 (  1.524704)

# Iterative:
#   0.000000   0.000000   0.000000 (  0.001934)