编写程序，求列表 s=[9,8,7,3,2,1,55,6]中元素的个数，最大值、最小值、元素之和、平均值。请至少写出三种实现方法。提示：①for循环；②while循环；③list的函数

方法一：for循环

s = [9,8,7,3,2,1,55,6]
count = 0
total = 0
max_num = s[0]
min_num = s[0]

for num in s:
count += 1
total += num
if num > max_num:
max_num = num
if num < min_num:
min_num = num

average = total / count

print("元素个数：", count)
print("最大值：", max_num)
print("最小值：", min_num)
print("元素之和：", total)
print("平均值：", average)

方法二：while循环

s = [9,8,7,3,2,1,55,6]
count = 0
total = 0
max_num = s[0]
min_num = s[0]
i = 0

while i < len(s):
count += 1
total += s[i]
if s[i] > max_num:
max_num = s[i]
if s[i] < min_num:
min_num = s[i]
i += 1

average = total / count

print("元素个数：", count)
print("最大值：", max_num)
print("最小值：", min_num)
print("元素之和：", total)
print("平均值：", average)

方法三：list函数

s = [9,8,7,3,2,1,55,6]
count = len(s)
total = sum(s)
max_num = max(s)
min_num = min(s)
average = total / count

print("元素个数：", count)
print("最大值：", max_num)
print("最小值：", min_num)
print("元素之和：", total)
print("平均值：", average)