Prime Quadruplet - kyoupuro @ ウィキ

0222 : Prime Quadruplet

問題文

解説

プログラム

C

C++

...

#include <iostream>
using namespace std;
 
const int MAX = 10000000;
bool prime[MAX+1];
 
void solve(int n) {
    if (prime[n]) return;
 
    for (int i = n*2; i <= MAX; i += n) {
        prime[i] = true;
    }
    return;
}

int main() {
    for (int i = 2; i*i <= MAX; i++) solve(i);
 
    int n;
    while (cin >> n, n) {
        if (n%2 == 0) n--;
        for (int i = n; i-8 >= 0; i -= 2) {
            if (prime[i]) continue;
 
            if (!prime[i] && !prime[i-2] && !prime[i-6] && !prime[i-8]) {
                cout << i << endl;
                break;
            }
        }
    }
 
    return 0;
}

Java