fibonacchi.rb

def testo(&block)
  min_time = nil
  total_time = 0
  1000.times do
    break if total_time > 10
    ti1 = Time.now
    res = block.call
    ti2 = Time.now
    if res == -1
      min_time = -1
      break
    end
    dt = ti2-ti1
    min_time=dt if (min_time||=dt) < dt
    total_time += dt
  end
  printf("%.5f ms\n", min_time*1000)
end

def t1
  (2..@n).reduce([0,1]){ |f| f << f.last(2).reduce(:+) }
end

def t2
  res = [] and Array.new(@n,0).each_with_index{|x,i| res << (i<2 ? i : res[i-1] + res[i-2])} and res
end 

def t3 
  res = [] and @n.times{|i| res << (i<2 ? i : res[i-1] + res[i-2])} and res
end

def t4
  return -1 if @n > 30
  f = -> (x){x<2 ? x : f[x-1] + f[x-2]} and (0..@n).map { |e| f[e] }
end

def t5
  i = Math.sqrt(5) and f = -> (x){(((((1 + i)/2)**x) - (((1-i)/2)**x)) / i).to_i} and (0..@n).map { |e| f[e] }
rescue FloatDomainError
  puts "FloatDomainError: Infinity"
  return -1
end

def dd(n)
  @n=n
  testo {t1}
  testo {t2}
  testo {t3}
  testo {t4}
  testo {t5}
end


def y1
  (2..@n).reduce([0,1]){ |f| f << f.last(2).reduce(:+) }[0]
end

def y2
  res = [] and Array.new(@n,0).each_with_index{|_x,i| res << (i<2 ? i : res[i-1] + res[i-2])} and res[-1]
end 

def y3 
  res = [] and @n.times{|i| res << (i<2 ? i : res[i-1] + res[i-2])} and res[-1]
end

def y4
  return -1 if @n > 30
  (f = -> (x){x<2 ? x : f[x-1] + f[x-2]})[@n]
end

def y5
  i = Math.sqrt(5) and (((((1 + i)/2)**@n) - (((1-i)/2)**@n)) / i).to_i
rescue FloatDomainError
  puts "FloatDomainError: Infinity"
  return -1
end

def yy(n)
  @n=n
  testo {y1}
  testo {y2}
  testo {y3}
  testo {y4}
  testo {y5}
end




def ttt4(x)
  x<2 ? x : ttt4(x-1) + ttt4(x-2)
end
def tty4
  (0..@n).map { |e| ttt4(e) }
end