/**

* Given a sorted linked list, delete all nodes that

* have duplicate numbers, leaving only distinct

* numbers from the original list.

* Example

* Given 1->2->3->3->4->4->5, return 1->2->5.

* Given 1->1->1->2->3, return 2->3.

**/

public class ListNode2 {

int val;

ListNode2 next;

ListNode2(int x) {

val = x;

next = null;

}

public static ListNode2 deleteDuplicates(ListNode2 head) {

// write your code here

if ((head == null) || (head.next == null)) {

return head;

}

ListNode2 dummy = new ListNode2(1);

dummy.next = head;

head = dummy;

while (head.next != null) {

if (head.next.val == head.next.next.val) {

head.next = head.next.next;

} else {

head = head.next;

}

}

return head;

}

public static void main(String[] args) {

/*

ListNode2 node0 = new ListNode2(1);

ListNode2 node1 = new ListNode2(1);

ListNode2 node2 = new ListNode2(2);

ListNode2 node3 = new ListNode2(3);

node0.next = node1;

node1.next = node2;

node2.next = node3;

// node3.next = null;

// node0 = deleteDuplicates(node0);

System.out.print(node0.val + "->" + node1.val + "->" + node2.val + "->" + node3.val);

*/

}

}