题解 | #质数因子#

最后一个2000000014超时问题，2000000014除以2 得1000000007，需要循环1000000006才能得到1000000007没有质数因子，
加判断素数，循环（int(sqrt(1000000007))+1 - 5）/ 6 = 5269 次，得1000000007不能再分解，直接输出

from math import sqrt 
def is_prime(n):
    if n < 2:
        return False
    if n == 2 or n == 3:
        return True
    if n % 6 != 1 and n % 6 != 5:
         return False
    for  i in range(5, int(sqrt(n))+1, 6):
        if n % i == 0 or n % (i + 2) == 0:
            return False
    return True

num = int(input())
term = []

if num == 1 or num == 2 or num ==3:
    result = num
else:
    for i in range(2,num//2+1):
        while num % i == 0:
            term.append(str(i))
            num = int(num / i)
        if is_prime(num):
            term.append(str(num))
            break
result = ' '.join(term)
print(result)