prime1_2.cpp

using namespace std;

#include <iostream>
#include <vector>
#include <set>
#include <cmath>

int main() {
    vector<int> primes;
    primes.push_back(2);

    for (int i = 3; i <= 32000; i+=2) {
        bool isprime = true;
        int cap = sqrt(i) + 1;

        vector<int>::iterator p;
        for (p = primes.begin(); p != primes.end(); p++) {
            if (*p >= cap) break;
            if (i % *p == 0) {
                isprime = false;
                break;
            }
        }
        if (isprime) primes.push_back(i);
    }

    int T,N,M;

    cin >> T;

    for (int t = 0; t < T; t++) {
        if (t) cout << endl;

        cin >> M >> N;
        if (M < 2) M = 2;

        int cap = sqrt(N) + 1;

        set<int> notprime;
        notprime.clear();

        vector<int>::iterator p;
        for (p = primes.begin(); p != primes.end(); p++) {

            if (*p >= cap) break;
            int start;

            if (*p >= M) start = (*p)*2;
            else start = M + ((*p - M % *p) % *p);

            for (int j = start; j <= N; j += *p) {
                notprime.insert(j);
            }
        }

        for (int i = M; i <= N; i++) {
            if (notprime.count(i) == 0) {
                cout << i << endl;
            }
        }

    }
    return 0;
}