题解 | #删除有序链表中重复的元素-I#

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

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