Submission

Score: 100

User: cheetah

Problemset: จำนวนเฉพาะก่อนหน้า

Language: cpp

Time: 0.052 second

Submitted On: 2026-07-18 23:10:48

#include<bits/stdc++.h>
using namespace std;

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

    int n;
    cin >> n;
    
    vector<bool> ar(n + 1, 1);
    ar[0] = 0;
    ar[1] = 0;

    for (int i = 2; i <= n; ++i) {
        ar[i] = 1;
    }

    for (int i = 2; i <= n; ++i) {
        if (ar[i] == 1) {
            for (int j = i + i; j <= n; j += i) {
                ar[j] = 0;
            }
        }
    }

    int ans[5];
    int cnt = 5, p = n - 1;
    while (cnt != 0) {
        if (ar[p] == 1) {
            --cnt;
            ans[cnt] = p;
        }
        --p;
    }
    
    for (int i = 0; i < 5; ++i) {
        cout << ans[i] << " ";
    }

    return 0;
}