2022-3-27 Leetcode 面试题01.移除重复节点

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* removeDuplicateNodes(ListNode* head) {
        set<int> mySet;
        ListNode* p = head;
        ListNode*pre;
        while(p){
            if(mySet.insert(p->val).second == false){
                p = p->next;
                pre->next = pre->next->next;
            }else{
                pre = p;
                p = p->next;
            }
        }
        return head;
    }
};