import java.util.*;

public class connectedComponents {

public static void main(String[] args){

generateLinkedList obj = new generateLinkedList();

int[] nums = new int[] {5,2,3,0};

int[] eles = new int[] {0,1,2,3,4,5};

ListNode head = obj.generate(eles);

System.out.println(numComponets(head, nums));

}

public static int numComponets(ListNode head, int[] G){

Set<Integer> nums = new HashSet<>();

for(int num : G){

nums.add(num);

}

int res = 0;

boolean prev = false;

ListNode dummy = new ListNode(0);

dummy.next = head;

while(head != null){

if(nums.contains(head.val)){

if(!prev){

res ++;

}

prev = true;

}else{

prev = false;

}

head = head.next;

}

return res;

}

}