Submission

Score: 85

User: Bestzu

Problemset: จำนวนเฉพาะก่อนหน้า

Language: cpp

Time: 0.045 second

Submitted On: 2025-10-15 11:53:38

#include <bits/stdc++.h>
#define endl '\n'
#define ll long long int
using namespace std;

vector<ll> prime;

void sieve(ll n) {
    vector<bool> is_prime(n+1, true);
    is_prime[0] = is_prime[1] = false;
    for(ll i = 2; i*i <= n; i++) {
        if(is_prime[i]) {
            for(ll j = i*i; j <= n; j += i)
                is_prime[j] = false;
        }
    }
    for(ll i = 2; i <= n; i++)
        if(is_prime[i]) prime.push_back(i);
}

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

    ll n; cin >> n;


    sieve(n);
    auto it = lower_bound(prime.begin(), prime.end(), n);

    for(int i = 5; i >= 1; i--) {
        cout << *(it - i) << " ";
    }
    cout << endl;

    return 0;
}