인프런 커뮤니티 질문&답변

package matter2_6;

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int count = sc.nextInt();
		int num[] =new int[count];
		for (int i = 0; i < count; i++) {
			num[i] = sc.nextInt();
		}
		
		
		Main main = new Main();
		main.solution(num);
		
	}
	
	public void solution(int [] num) {
		int arr[] = new int [num.length];
		for (int i = 0; i < num.length; i++) {
			for (int j = 0; j <3; j++) {
				if(num[i] > 0) {
					arr[i] *= 10;
					arr[i] += num[i]%10;
					num[i] /= 10;
				}
			}
			if(!isPrime(arr[i])) arr[i] = 0;
		}
		
		for (int i = 0; i < arr.length; i++) {
			if(arr[i]!=0)
			System.out.print(arr[i]+" ");
		}
	}
	
	public boolean isPrime(int a) {
		if(a==1) return false;
		for(int i = 2;i<a;i++) {
			if(a%i==0) return false;
		}
		return true;
	}
}

잘못 된 곳을 못찾겠습니다.