筛法求素数

import java.util.Scanner;

/**
 * @date 2020/3/4 - 下午 10:40
 */
public class 筛法求素数 {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        int[] a=new int[n+1];
        for (int i = 2; i <=n; i++) {
            if (a[i]==0){
                System.out.println(i);
                for (int j = 2; j*i<=n; j++) {//把索引是i的倍数都标记出来
                    a[i*j]=1;
                }
            }

        }
    }
}