src/main/java/A2_AddTwoNumbers.java

public class A2_AddTwoNumbers {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2){
        ListNode res = new ListNode(-1);
        ListNode cur = res;
        int carray = 0;
        while(l1 != null && l2 != null){
            int d1 = l1 == null ? 0 : l1.val;
            int d2 = l2 == null ? 0 : l2.val;
            int sum = d1 + d2 + carray;
            carray = sum >= 10 ? 1 : 0;
            cur.next = new ListNode(sum % 10);
            cur = cur.next;
            if(l1 != null) l1 = l1.next;
            if(l2 != null) l2 = l2.next;
        }
        if(carray == 1)
            cur.next = new ListNode(1);
        return res;
    }

    public static void main(String[] args) {
        int x = 3, y = 6, z;
        z = x^y<<2;
        System.out.println(z);
    }
}