Submission

Score: 100

User: nuxh

Problemset: จำนวนเฉพาะก่อนหน้า

Language: cpp

Time: 0.002 second

Submitted On: 2026-10-13 00:06:40

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

bool isPrime(int n){
    if(n <= 1) return false;
    if(n <= 3) return true;
    if(n %2 == 0 || n%3 == 0) return false;
    for(int i = 5 ; i*i <= n ; i+=6){
        if(n%i == 0 || n%(i+2) == 0){
            return false;
        }
    }
    return true;
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;


   int cnt  = 0;
   vector<int> a(5);
    for(int i = n-1; i >= 2 && cnt < 5; i--){
        if(isPrime(i)){
        a.push_back(i);
        cnt++;
    }
}
    reverse(a.begin(),a.end());
    for(int i = 0 ; i< 5 ; i++){
        cout << a[i] << " ";
    }
}