蛮力法——狱吏问题

public class Demo {
	public static void main(String[] args) {
		int n;
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		sc.close();
		int[] flag = new int[n + 1];
		for(int i = 1;i<=n;i++) {
			for(int j = i;j<=n;j = j+i) {
				flag[j] = 1 - flag[j];
			}
		}
		for(int i = 1;i<= n;i++) {
			if(flag[i] == 1)
				System.out.print(i + " ");
		}
		System.out.println();
		answer_two(n);
	}
	public static void answer_two(int n) {
		int i;
		for(i = 1;i<=n;i++)
		{
			if(i * i <= n)
				System.out.print(i*i + " ");
			else
				break;
		}
	}