[LeetCode]83 Remove Duplicates from Sorted List

/**
* Definition for singly-linked list.
* public class ListNode {
*     int val;
*     ListNode next;
*     ListNode(int x) {
*         val = x;
*         next = null;
*     }
* }
*/
public class Solution {
public ListNode deleteDuplicates(ListNode head) {
ListNode pre = null;
ListNode node = head;
while (node != null)
{
if (pre == null)
{
pre = node;
node = node.next;
}
else if (pre.val == node.val)
{
// Delete node
pre.next = node.next;
node.next = null;
node = pre.next;
}
else
{
pre = node;
node = node.next;
}
}
return head;
}
}