/**
* struct ListNode {
* int val;
* struct ListNode *next;
* ListNode(int x) : val(x), next(nullptr) {}
* };
*/
class Solution {
public:
/**
* 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
*
*
* @param head ListNode类
* @return ListNode类
*/
ListNode* deleteDuplicates(ListNode* head) {
if (head == nullptr) return nullptr;
ListNode* left = head, *right = head;
while (right!=nullptr) {
if (left == right or left->val == right->val) {
right = right->next;
continue;
}
left->next = right;
left = right;
}
left->next = right;
left = right;
return head;
}
};