Python-递归

# 设置递归深度
# sys.setrecursionlimit(1000)

# 求阶乘
# 1.非递归版本
def factorial(n):
    result = n
    for i in range(1, n):
        result *= i
        continue
    print(n, ‘的阶乘为：‘, result)
print(factorial(10))

# 2.递归版本(求n的阶乘)
def factorial1(n):
    if n ==1:
        return 1
    else:
        return n * factorial1(n - 1)
n = int(input(‘请输入一个正整数：‘))
answer = factorial1(n)
print(n, ‘的阶乘为：‘, answer)


# 斐波那契数列
# 1.递归版本
def fun1(n):
    if n == 1 or n ==2:
        return 1
    else:
        return fun1(n-1) + fun1(n-2)
for n in range(1,20):
    a = fun1(n)
    print(‘斐波那契数列的第‘, n, ‘位是‘,a)
# 2.迭代版本
def fun2(n):
    n1 = 1
    n2 = 1
    n3 = 1
    if n < 1:
        print(‘输入有误，请重新输入！‘)
        return -1
    else:
        while n - 2 > 0:
            n3 = n1 + n2
            n1 = n2
            n2 = n3
            n -= 1
        return n3
n = int(input(‘请输入已经经过的月份：‘))
result = fun2(n)
if result !=-1:
    print(‘总共有%d只小兔崽子‘% result)

# 汉诺塔游戏
def hanoi(n, x, y, z):#x:初始位置；y：目标位置；z：借用位置
    if n == 1:
        print(x, ‘-->‘, z)
    else:
        hanoi(n-1, x, z, y)# 将n-1个盘子从X移到Y
        print(x, ‘-->‘, z) #将第n个盘子从X移到Z
        hanoi(n-1, y, x, z)# 将n-1个盘子从Y移到Z
n = int(input(‘请输入汉诺塔的层数：‘))
hanoi(n, ‘a‘, ‘b‘, ‘c‘)