题解 | 牛牛的数学作业

def fangcha(m,content):
    pingjun = sum(content)/m
    fangchajuzheng = [0]*m
    for i in range(m):
        fangchajuzheng[i] = (content[i]-pingjun)*(content[i]-pingjun)
        fangcha = sum(fangchajuzheng)/m
    return fangcha


n = int(input())
char = [0]*n


for i in range(n):
    m = int(input())
    content = sorted(list(map(int, input().split())))
    print(f"{content[m-1]-content[0]} {fangcha(m,content):.3f}")