Leetcode: Remove Duplicates from Sorted List II

Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.

For example,
Given 1->2->3->3->4->4->5, return 1->2->5.
Given 1->1->1->2->3, return 2->3.

class Solution {
public:
    ListNode *deleteDuplicates(ListNode *head) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        ListNode dummy(0);
        dummy.next = head;

        ListNode *pre = &dummy, *cur = head;
        while (cur) {
            int i = cur->val;
            if (cur->next && cur->next->val == i) {
                while (cur && cur->val == i) {
                    pre->next = cur->next;
                    delete cur;
                    cur = pre->next;
                }
                cur = pre;
            }
            pre = cur;
            cur = cur->next;
        }

        return dummy.next;
    }
};

 

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