2019-01-10 Day 5

Day 5 01-10-2019
来源：LeetCode
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。

示例 1:

输入: 1->1->2
输出: 1->2
示例 2:

输入: 1->1->2->3->3
输出: 1->2->3

/**
 * 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 * cur , *next ;
        cur = head ; next = head->next ;
        
        for( ; next != NULL ; next = next -> next )
        {
            if( cur -> val != next -> val) //如果两数不相等
            {
                cur -> next = next;
                cur = cur -> next;                
            }
        }
        cur->next = NULL;
        
        return head ;
    }
};