83

给定一个排序链表，删除所有重复的元素，使得每个元素只出现一次。

/**
 * 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) {
    if (head == NULL ||head->next == NULL)
    {
        return head;
    }
    ListNode *test = head;
    while (test->next!= NULL)
    {
        if (test->val == (test->next)->val)
            test->next = test->next->next;
        else
            test = test->next;
    }
    return head;
    }
};