链表

//Node
public class Node {
  public int data; //若设为private另一个类无法访问
    public Node next;
   public Node(int data) {
     this.data = data;
   }
}

//主类
public class PrintCommonPart {
  public static void printCommonPart(Node head1, Node head2) {
        while (head1 != null && head2 != null) {
            if (head1.data < head2.data) {
                head1 = head1.next;
            } else if (head1.data > head2.data) {
             head2 = head2.next;
         } else { //head1.data == head2.data
             System.out.println("相同的数据：" + head1.data);
              head1 = head1.next;
             head2 = head2.next;
         }
       }
   }
   //Test
  public static void main(String[] args) {
       Node head1 = new Node(1); //注意链表中个各结点的指向
        Node node1 = new Node(2);
       Node node2 = new Node(3);
       Node node3 = new Node(4);
       head1.next = node1;
     node1.next = node2;
     node2.next = node3;
     Node head2 = new Node(3);
       Node node4 = new Node(3);
       Node node5 = new Node(3);
       Node node6 = new Node(4);
       head2.next = node4;
     node4.next = node5;
     node5.next = node6;
     printCommonPart(head1, head2);
  }
}