题解 | #删除有序链表中重复的元素-I#

一次遍历

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

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