Fibonacci Sequence

I used my instincts to write this fibonacci sequence generator using an array. I’m aware there are simpler solutions not using an array. I used an array because originally I wanted to output the entire array (e.g., [0,1,1,2,3]).

Using Iteration
—————

def fibonacci(input)

  return input if input == 0 || input == 1

  array_of_results = [0,1]
  i = 1
  
  until i == input
    next_node = array_of_results[-1] + array_of_results[-2]
    array_of_results.push(next_node)
    i += 1
  end

  return array_of_results.last
end

p fibonacci(11) #=> returns 89

Recursive
———

def fibonacci_recursive(input)
return input if input == 0 || input == 1
fibonacci_recursive(input-1) + fibonacci_recursive(input-2) if input > 1
end

p fibonacci_recursive(11) #=> returns 89

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