Submission

Score: 100

User: Dormon

Problemset: Twin, Cousin, and Sexy Prime

Language: cpp

Time: 0.420 second

Submitted On: 2025-10-14 19:30:44

#include <iostream>
#include <vector>

using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int l, r;
    cin >> l >> r;
    vector<bool> seive(r + 10, true);
    seive[0] = seive[1] = false;
    for (int i = 2;i <= r + 6;i++){
        if (!seive[i]) continue;
        for (int j = 2 * i;j <= r + 6;j += i)
            seive[j] = false;
    }

    int a1 = 0, a2 = 0, a3 = 0;
    for (int i = l;i <= r;i++){
        if (!seive[i]) continue;
        a1 += (i >= 5 && seive[i - 2]) || seive[i + 2];
        a2 += (i >= 7 && seive[i - 4]) || seive[i + 4];
        a3 += (i >= 9 && seive[i - 6]) || seive[i + 6];
    }
    cout << a1 << '\n' << a2 << '\n' << a3 << '\n';
}