C++ 代码

结构体，不delete是不能忍的

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* deleteDuplication(ListNode* head) {
        if(head == nullptr || head->next == nullptr) return head; //0 or 1
        //2 or more
        ListNode * head1 = new ListNode(0);
        head1->next = head;

        ListNode * p = head;
        ListNode * b_p = head1;

        while((p != nullptr) && (p->next != nullptr)){
            if(p->val != p->next->val){
                b_p = b_p->next;
                p = p->next;
            }
            else{//p->val == p->next->val
               while((p->next != nullptr)&&(p->val == p->next->val) ) {
                   ListNode * t = p;
                   p = p->next;
                   delete(t);
               }
               ListNode * t = p;
               p = p->next;
               delete(t);
               b_p->next = p;
            }
        }
        return head1->next;
    }
};