题解 | 查找组成一个偶数最接近的两个素数

def find_prime(n):

    sieve = [True] * (n+1)
    sieve[0] = sieve[1] = False

    for i in range(2,int(n ** 0.5)+1):
        if sieve[i]:
            for k in range(i*i,n+1,i):
                sieve[k] = False

    a = n // 2
    for _ in range(n//2):
        if sieve[a] and sieve[n-a]:
            return a,n-a
        a -= 1
    return 2,2

n = int(input())
a, b = find_prime(n)
print(a)
print(b)