Leetcode: Remove Duplicates from Sorted List

Given a sorted linked list, delete all duplicates such that each element appear only once.

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

class Solution {
public:
    ListNode *deleteDuplicates(ListNode *head) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        if (!head) return NULL;
        ListNode *pre = head, *cur = head->next;
        while (cur) {
            if (cur->val == pre->val) {
                pre->next = cur->next;
                delete cur;
                cur = pre;
            }
            pre = cur;
            cur = cur->next;
        }

        return head;
    }
};

 

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