leetcode83

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     public int val;
 *     public ListNode next;
 *     public ListNode(int x) { val = x; }
 * }
 */
public class Solution {
    public ListNode DeleteDuplicates(ListNode head)
    {
        //if (head == null || head.next == null)
            //{
            //    return head;
            //}
            //head.next = DeleteDuplicates(head.next);

            //if (head.val == head.next.val)
            //{
            //    return head.next;
            //}
            //else
            //{
            //    return head;
            //}

            if (head != null)
            {
                var cur = head;
                var next = head.next;                
                while (next != null)
                {
                    if (cur.val == next.val)
                    {
                        cur.next = next.next;//对原链表的修改                        
                    }
                    else
                    {
                        cur = next;//移动指针                        
                    }
                    next = next.next;//移动指针
                }
            }
            return head;
    }
}

https://leetcode.com/problems/remove-duplicates-from-sorted-list/#/description

补充一个python的实现：

class Solution:
    def deleteDuplicates(self, head: ListNode) -> ListNode:
        if head == None:
            return None
        cur = head
        nextnode = head.next
        while nextnode != None:
            if cur.val == nextnode.val:
                cur.next = nextnode.next
            else:
                cur = nextnode
            nextnode = nextnode.next
        return head