Submission

Score: 0

User: tl.cpp

Problemset: จำนวนเฉพาะก่อนหน้า

Language: cpp

Time: 0.003 second

Submitted On: 2026-10-04 22:55:08

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e7 + 5;
int n;
int isPrime[N];
set<int> s;

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

    cin >> n;
    isPrime[0] = isPrime[1] = 1;
    for (int i = 2; i * i < N; i++) {
        if (!isPrime[i]) {
            for (int j = i * 2; j < N; j += i) {
                isPrime[j] = 1;
            }
        }
    }
    for (int i = n; i >= 2; i--) {
        if (!isPrime[i]) {
            s.insert(i);
            if (s.size() == 5) break;
        }
    }
    for (auto c : s) cout << c << ' ';
}