编写两个函数，其功能分别为： ⑴ 求N个整数的次大值和次小值 ⑵ 求两个整数的最大公约数和最小公倍数

⑴ 求N个整数的次大值和次小值：

def find_second_largest_smallest(numbers):
    # 求次大值
    largest = second_largest = float('-inf')
    for num in numbers:
        if num > largest:
            second_largest = largest
            largest = num
        elif num > second_largest and num != largest:
            second_largest = num
    
    # 求次小值
    smallest = second_smallest = float('inf')
    for num in numbers:
        if num < smallest:
            second_smallest = smallest
            smallest = num
        elif num < second_smallest and num != smallest:
            second_smallest = num
    
    return second_largest, second_smallest

⑵ 求两个整数的最大公约数和最小公倍数：

def gcd_lcm(a, b):
    # 求最大公约数
    def gcd(x, y):
        while y:
            x, y = y, x % y
        return x
    
    # 求最小公倍数
    def lcm(x, y):
        return x * y // gcd(x, y)
    
    return gcd(a, b), lcm(a, b)