Submission

Score: 0

User: TonnamSora

Problemset: จำนวนเฉพาะก่อนหน้า

Language: cpp

Time: 0.022 second

Submitted On: 2025-10-10 08:53:09

#include <iostream>
using namespace std;

int main(){
    int N;
    cin >> N;
    int a[N + 1] = {0};
    for(int i = 2; i <= N; i++){
        if(a[i] == 0){
            for(int j = i + i; j <= N; j+=i){
                a[j] = 1;
            }
        }
    }
    int count = 0;
    for(int i = 2; i <= N; i++){
        if(a[i] != 1){
            cout << i << ", ";
            count++;
        }
    }
    cout << "\n" << count;
    /*int idx = N - 1;
    int cnt = 0;
    int c[5];*/
    /*while(cnt < 5 && idx >= 2){
        if(a[idx] != 1){
            c[cnt] = idx;
            cnt++;
        }
        idx--;
    }
    for(int i = 4; i >= 0; i--){
        cout << c[i] << " ";
    }*/
}