Python3 实例

# 1. 九九乘法表
for i in range(1, 10):
    line = ""
    for j in range(1, i + 1):
        line += f"{j}x{i}={i*j}\t"
    print(line)

# 2. 斐波那契数列（前 n 项，迭代写法）
def fib(n):
    a, b = 0, 1
    result = []
    for _ in range(n):
        result.append(a)
        a, b = b, a + b
    return result

print(fib(8))   # [0, 1, 1, 2, 3, 5, 8, 13]

# 3. 判断质数（只需试除到平方根，效率更高）
def is_prime(n):
    if n < 2:
        return False
    for i in range(2, int(n ** 0.5) + 1):
        if n % i == 0:
            return False
    return True

print([x for x in range(2, 20) if is_prime(x)])
# [2, 3, 5, 7, 11, 13, 17, 19]

# 4. 阶乘（递归 + 终止条件）
def factorial(n):
    if n <= 1:
        return 1
    return n * factorial(n - 1)

print(factorial(5))   # 120

# 5. 字符串反转与回文判断
s = "hello"
print(s[::-1])              # olleh
def is_palindrome(word):
    return word == word[::-1]
print(is_palindrome("level"))   # True

# 6. 水仙花数（各位数字立方和等于自身）
for n in range(100, 1000):
    a, b, c = n // 100, n // 10 % 10, n % 10
    if a**3 + b**3 + c**3 == n:
        print(n, end=" ")    # 153 370 371 407

# 7. 汉诺塔（经典递归）
def hanoi(n, src, dst, helper):
    if n == 1:
        print(f"{src} -> {dst}")
        return
    hanoi(n - 1, src, helper, dst)
    print(f"{src} -> {dst}")
    hanoi(n - 1, helper, dst, src)

hanoi(2, "A", "C", "B")

# 8. 猜数字游戏（交互）
import random

target = random.randint(1, 100)
while True:
    guess = int(input("猜一个 1-100 的数字: "))
    if guess < target:
        print("小了")
    elif guess > target:
        print("大了")
    else:
        print("猜对了！")
        break