Submission

Score: 0

User: lumppengae

Problemset: จำนวนเฉพาะก่อนหน้า

Language: cpp

Time: 0.030 second

Submitted On: 2026-10-06 11:32:06

#include <bits/stdc++.h>
using namespace std;
int main(){
    long long a;
    cin>>a;
    vector<bool> b(a+1,true);
    b[0]=false;
    b[1]=false;
    for (long long i = 2; i * i <= a; i++) { // Fixed: i * i <= a
        if (b[i]) {
            for (long long j = i * i; j <= a; j += i) {
                b[j] = false;
            }
        }
    }
    a-=1;
    int i=5;
    while(i!=0){
        if(b[a]){
            cout<<a<<" ";
            i--;
        }
        a--;
    }
}