两种方式实现斐波那契数列

def fibonacci(n): 
    if n == 0: 
        return 0 
    if n == 1: 
        return 1 
    res = f(n-1) + f(n-2) 
    return res 
print(fibonacci(10)) 

def fibonacci(n): 
    a, b = 0, 1 
    count = 0 
    while count < n: 
        num = a 
        count += 1 
        a,b = b,a+b 
        yield num 

n = int(input()) + 1 
fib = fibonacci(n) 
num = None 
for i in range(n): 
    num = next(fib) 
print(num) 

a,b = 0,1 
for i in range(n): 
    a,b = b,a+b 
print(a)