AC

迷彩服阿绿  •  6天前


include

include

using namespace std;

bool p[10005];

void isprime(int n) {

memset(p, true, sizeof(p));
p[0] = p[1] = false;
for (int i = 2; i * i <= n; ++i) {
	if (p[i]) {
		for (int j = i * i; j <= n; j += i) {
			p[j] = false;
		}
	}
}

}

int main() {

int n;
cin >> n;
isprime(n);
for (int i = 2; i + 2 <= n; ++i) {
	if (p[i] && p[i + 2]) {
		cout << i << ' ' << i + 2 << endl;
	}
}

return 0;

}


评论:

请先登录,才能进行评论