比较简单 没啥好注意的

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */

class Solution {
public:
    /**
     * 
     * @param head ListNode类 
     * @return ListNode类
     */
    ListNode* deleteDuplicates(ListNode* head) {
        // write code here
        ListNode* cur = head;
        if(!head)
            return nullptr;
        while(cur->next){
            if(cur->val == cur->next->val){
                cur->next = cur->next->next;
            }
            else
                cur =cur->next;
        }
        return head;
    }
};