Task1

import java.util.*;

public class Main {
    public static void main(String[] args) {
        System.out.println(joinTableWithoutPrimes(new int[]{2,3,9,2,5,1,3,7,10}, new int[]{2, 1, 3, 4, 3, 10, 6, 6, 1, 7, 10, 10, 10}));
    }

    static List<Integer> joinTableWithoutPrimes(int[] A, int[] B){

        //Declaration and variable assignment
        int aLength = A.length;
        int bLength = B.length;
        List<Integer> C = new LinkedList<>();
        Map<Integer, Integer> bExistTimesMap = new HashMap<>();

        //Creating map holding Key(Integer from B array) and Value(quantity of Key existing in B array)
        for (int i=0; i<bLength; i++) {
            if (i==0 || !bExistTimesMap.containsKey(B[i])){
                bExistTimesMap.put(B[i], 1);
            } else {
                bExistTimesMap.replace(B[i], bExistTimesMap.get(B[i])+1);
            }
        }

        //Checking if each element of array A exist in B array(map created before), and if so, counting if prime number of times.
        for (int i = 0; i<aLength; i++) {
            if (bExistTimesMap.containsKey(A[i]) && isPrime(bExistTimesMap.get(A[i]))){
                continue;
            } else {
                C.add(A[i]);
            }
        }
        return C;
    }

    //Method for prime number verification
    static boolean isPrime(int x){
        if (x<2 || (x%2==0 && x!=2)) {
            return false;
        }
        for(int i=3;i*i<=x;i+=2) {
            if(x%i==0)
                return false;
        }
        return true;
    }
}