迷彩服阿绿 • 6天前
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