leetCode #82 Remove Duplicates from Sorted List

题目：从一个有序链表里删除重复元素

分析：这个和数组去重很像。都只需记录下当前不重复的元素位置到下一个不重复的元素位置，然后建立联系即可。

答案：

/** * 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* pre = head;                if (head == NULL)            return head;        ListNode* nextp = head->next;                while(nextp){            if (nextp->val == pre->val){                nextp = nextp->next;                pre->next = NULL; // 临时先指向null            }            else{                pre->next = nextp;                 pre = pre->next;                nextp = nextp->next;            }        }        return head;    }};