python中斐波那契数列中大于N的最小值

Question

我希望从其他练习网站解决这个问题。我是 python 新手。 将斐波那契数列视为 1,2,3,5,8,13,21,34,55,89... 我想打印值不超过 N（例如 N=10）的 (1) 斐波那契数列，求偶数项的总和。

(2)和大于N的最小值。

我已经写了以下代码：

N = 10
def fibonacci(n):
    if n in fibonacci_cashe: 
        return fibonacci_cashe[n]
    if n==1:
        value = 1
    elif n == 2:
        value = 1
    elif n>2:
        value = fibonacci(n-2)+fibonacci(n-1)

    fibonacci_cashe[n] = value
    return value 
for i in range(N):
    test = fibonacci(N)
    #I don't know what I should do here

例如，对于 N=10：

系列是1,2,3,5,8,13,21,34,55,89, 144, 144+89, ... 甚至小于（N=10）的是：2, 8, 34，它们的总和是 44。 大于（N=10）的最小的是：13

你能帮我解决这个问题吗？

非常感谢

Answer 1

def fibonacci(n):
   if n == 1 or n == 2:
        return 1
   return fibonacci(n - 1) + fibonacci(n - 2)


N = 10
result = []
total = 0
smallest = 1
for i in range(1, N + 1):
   term = fibonacci(i)
   if term < N:
        result.append(fibonacci(i))
        # also sum the even valued term
        if term % 2 == 0:
            total += term
    else:
        # term exceeded the limit N
        # so the term for which we exceeded the limit
        # is actually the smallest term greater than N
        # or you can say it is the first term which is greater than N
        smallest = term
        break
print(*result)
print('sum of even terms :', total)
print('smallest value greater than N:', smallest)

带记忆功能

def fibonacci(n):
if n == 1 or n == 2:
    fibonacci_cashe[n] = 1
if fibonacci_cashe[n] != 0:
    return fibonacci_cashe[n]

fibonacci_cashe[n] = fibonacci(n - 1) + fibonacci(n - 2)
return fibonacci_cashe[n]


N = 10
fibonacci_cashe = [0]*N # for memorization
result = []
total = 0
smallest = 1
for i in range(1, N + 1):
    term = fibonacci(i)
    if term < N:
        result.append(fibonacci(i))
        # also sum the even valued term
        if term % 2 == 0:
            total += term
    else:
        # term exceeded the limit N
        # so the term for which we exceeded the limit
        # is actually the smallest term greater than N
        # or you can say it is the first term which is greater than N
        smallest = term
        break
print(*result)
print('sum of even terms :', total)
print('smallest value greater than N:', smallest)

输出

1 1 2 3 5 8
sum of even terms : 10
smallest value greater than N: 13