LeetCode | Remove Duplicates from Sorted List

https://leetcode.com/problems/remove-duplicates-from-sorted-list/?tab=Description

注意dummy node的使用。

class Solution {
public:
    ListNode* deleteDuplicates(ListNode* head) {
        if (!head || !head->next) return head;
        
        ListNode dummy(0); dummy.next = head;
        while (head) {
            ListNode *p = head->next;
            while (p && p->val == head->val) {
                p = p->next;
                head->next = p;
            }
            head = p;
        }
        
        return dummy.next;
    }
};