题目：

输入数据n（n>=6）代表n个数，从0-9任意输入n个数，然后在n个数选出6个数xx-xx-xx表示 时：分：秒，求出最小时间和最大时间，若时间无效，则输出时间无效，例如： 

输入： 

import randomdef min_max_date(n):    if n < 6:        return "valid n"    nums = []    for i in range(n):        nums.append(int(random.random() * 10))    mind = min_date(nums)    maxd = max_date(nums)    print mind, maxddef min_date(nums):    nums = sorted(nums)    print nums    if nums[0] > 2:        return "valid date"    if nums[1] > 3:        return "valid date"    h_1 = nums[0]    h_2 = nums[1]    nums = nums[2:]    if nums[0] > 5:        return "valid date"    m_1 = nums[0]    nums = nums[1:]    if nums[1] > 5:        m_2 = nums[1]        nums.pop(1)    else:        m_2 = nums[0]        nums.pop(0)    if nums[0] > 5:        return "valid date"    s_1 = nums[0]    s_2 = nums[1]    return "%s%s:%s%s:%s%s" % (h_1, h_2, m_1, m_2, s_1, s_2)def max_date(nums):    h_1 = gen(0, 2, nums)    if h_1 is None:        return "valid date"    h_2 = gen(0, 3, nums)    if h_2 is None:        return "valid date"    m_1 = gen(0, 5, nums)    if m_1 is None:        return "valid date"    m_2 = gen(0, 9, nums)    if m_2 is None:        return "valid date"    s_1 = gen(0, 5, nums)    if s_1 is None:        return "valid date"    s_2 = gen(0, 9, nums)    if s_2 is None:        return "valid date"    return "%s%s:%s%s:%s%s" % (h_1, h_2, m_1, m_2, s_1, s_2)def gen(s, e, nums):    n = None    for i in range(len(nums)):        num = nums[i]        if s <= num <= e:            n = num        else:            nums.pop(i - 1)            break    return nmin_max_date(10)

其实最小值也可按求最大值方式取，客户们自己动手吧