83.Remove Duplicates from Sorted List

Tags: Easy Link List

Link: https://leetcode.com/problems/remove-duplicates-from-sorted-list/

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

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Example 1:

Input: 1->1->2
Output: 1->2

Example 2:

Input: 1->1->2->3->3
Output: 1->2->3

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Answer:

/**
 * 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) {
        ListNode *dummy = new ListNode(INT_MAX);
        dummy -> next = head;
        ListNode *pre, *cur;
        pre = dummy;
        cur = pre -> next;

        while(cur)
        {
            if(pre -> val == cur -> val){
                cur = cur -> next;
                pre -> next = cur;
            }
            else{
                cur = cur -> next;
                pre = pre -> next;
            }
        }

        return dummy -> next;
    }
};

解析：

这样做Runtime: 12 ms, faster than 100.00% of C++ online submissions for Remove Duplicates from Sorted List.。