# 比较占内存
w = int(input("输入一个数字还你一个斐波那契数列："))
list_res = []
def list_n(n):
  if n>=3:
    res=list_n(n-1)+list_n(n-2)
  else:
    res=1
  return res
 
print("开始")
 
for i in range(0,w):
  list_res.append(list_n(i+1))
print(list_res)

# 比较占内存
num =int(input("输入一个数字还你一个斐波那契数列v2.0："))
list_nums=[1,1]
def calculate(num,list_nums):
  i = 0
  if num>2:
    while i < num:
      list_nums.insert(i+2,list_nums[i]+list_nums[i+1])
      i+=1
    else:
      print("数列已生成")
      print(list_nums)
    return list_nums[num-1]
  else:
    return list_nums[0]
 
res = calculate(num,list_nums)
print("="*50)
print("第%s个:%s"%(num,res))

#省内存
def fbnq(n):
  a,b=1,1
  if n==1 or n ==2:
    return 1
  else:
    i=3
    while i<=n:
      a,b=b,a+b
      i+=1
    return b
 
print(fbnq(int(input("输入一个数："))))
 

"""实现斐波那契数列"""
 
 
class feibo(object):
  def __init__(self, length):
    self.num1 = 0
    self.num2 = 1
    self.num = self.num1
    self.length = length
    self.index = 0
 
  def __iter__(self):
    return self
 
  def __next__(self):
    self.num = self.num1
    while True:
      if self.index == self.length:
        raise StopIteration
      self.num1, self.num2 = self.num2, self.num1+self.num2
      self.index += 1
      return self.num
 
 
myfbnq = feibo(10)
# print(list(myfbnq))  # 指针位置已到最后一位
for i in myfbnq:
  print(i)