LeetCode – Refresh – Remove Duplicates from Sorted List

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode *deleteDuplicates(ListNode *head) {
        if (!head || !head->next) return head;
        ListNode *runner = head;
        while (runner->next) {
            if (runner->val == runner->next->val) {
                runner->next = runner->next->next;
                continue;
            }
            runner = runner->next;
        }
        return head;
    }
};