删除排序链表中的重复元素#83

输入: 1->1->2
输出: 1->2

输入: 1->1->2->3->3
输出: 1->2->3

//C style
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */
struct ListNode* deleteDuplicates(struct ListNode* head) {
     // write your code here
    if(head==NULL)
        return 0;
    if(head->next==NULL)
        return head;
    struct ListNode *cur=head;
    struct ListNode *pre=NULL;
    while(cur!=NULL)
    {
        if(pre!=NULL&&pre->val==cur->val)
        {
            pre->next=cur->next;
        }
        else
        {
            pre=cur;
        }
        cur=cur->next;
    }
    return head;
}

1->1->2->3->3

1->2->3