遞歸函數習題

# 階乘


def fn(n):
    if n == 1:
        return 1
    else:
        return n * fn(n-1)


print(fn(5))


def factorila(a, mul=1):
    mul *= a
    if a == 1:
        return mul

    return factorila(a-1, mul)


print(factorila(4))


def fac2(m, p=None):
    if p is None:
        p = 1
    if m == 1:
        return p
    p *= m
    print(p)
    fac2(m-1, p)
    return p


fac2(5)

# 1234 ==> [4,3,2,1]

def change(num, lst=[]):
    if len(str(num)) != 0 and num != 0:
        lst.append(num % 10)
        change(num//10, lst)
    return lst


print(change(1234))


# print(divmod(10, 5))  (2, 0)
def change(num, lst=[]):
    a, b = divmod(num, 10)
    if b == 0:
        return lst
    lst.append(b)
    return change(a, lst)


print(change(123888))


def change(num, lst=[]):
    if num:
        lst.append(num[-1])
        print(lst)
        change(num[:len(num)-1])
    return lst


print(change(str(1234)))

# 猴子吃桃子


def peach(days=10):
    if days == 1:
        return 1
    return (peach(days-1)+1)*2


print(peach())


def monkey(n=10):
    if n == 1:
        return 1
    return (monkey(n-1)+1)*2


print(monkey())


def fn(d=1):
    if d == 10:
        return 1
    return (fn(d+1)+1)*2


print(fn())


def fn(d=1, s=1):
    s = (s+1)*2
    d += 1
    if d == 10:
        return s
    return fn(d, s)


print(fn())