素数

欧式筛法求素数

def euler_primary(n):
    """
    记录[0,n)之间的素数
    """
    is_primary = [1]*(n+1)
    is_primary[0] = is_primary[1] =0
    primary = []
    for num in range(2, n):
        if is_primary[num]:
            primary.append(num)
        for prime in primary:
            if num * prime > n:
                break
            is_primary[num * prime] = 0
            if num % prime == 0:
                break
    return primary

print(euler_primary(998))

• 时间复杂度：O(n)
• 空间复杂度：O(n)