Submission

Score: 100

User: cyblox_boi

Problemset: จำนวนเฉพาะก่อนหน้า

Language: cpp

Time: 0.031 second

Submitted On: 2025-10-22 23:31:59

#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

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

	long long n;
	cin >> n;

	vector<bool> prime(n + 1, true);
	prime[0] = prime[1] = false;

	for (int p = 2; p * p <= n; p++) {
		if (prime[p]) {
			for (int i = p * p; i <= n; i += p) {
				prime[i] = false;
			}
		}
	}

	vector<long long> primeNumbers;

	for (long long i = n - 1; primeNumbers.size() < 5; i--) {
		if (prime[i]) {
			primeNumbers.push_back(i);
		}
	}

	reverse(primeNumbers.begin(), primeNumbers.end());

	for (const long long &i : primeNumbers) {
		cout << i << ' ';
	}

	cout << '\n';

	return 0;
}