删除链表重复节点

/**
 * 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) {
        if(head==null || head.next == null)
            return head;
         ListNode cur = head;
        while(cur != null){
            while(cur.next != null && cur.val == cur.next.val){
                cur.next = cur.next.next;
            }
            cur = cur.next;
        }
        return head;
    }
}

2.删除重复节点 ，去除重复节点本身

/**
 * 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) {
        if(head == null || head.next ==null)
            return head;
         ListNode FakeHead=new ListNode(0);
         FakeHead.next=head;
         ListNode pre=FakeHead;
         ListNode cur=head;
        while(cur!=null){ 
            while(cur.next!=null&&cur.val==cur.next.val){
                 cur=cur.next;
            }
            if(pre.next==cur){
                 pre=pre.next;
            }else{
                 pre.next=cur.next;
            }
             cur=cur.next;         
      }
        return FakeHead.next;
    }
}