83. 删除排序链表中的重复元素

链接

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */
struct ListNode* deleteDuplicates(struct ListNode* head){
    if(head == NULL) 
    {
        return head;
    }
    struct ListNode *pre = head;
    while(pre->next != NULL)
    {   
        if(pre->val == pre->next->val)
        {
            pre->next = pre->next->next;
        }
        else
        {
            pre = pre->next;
        }    
    }
    return head;
}