题解 | 牛群排列去重

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param head ListNode类 
 * @return ListNode类
 */
struct ListNode* deleteDuplicates(struct ListNode* head ) {
    // write code here
    struct ListNode *p;    
    struct ListNode *pPrev = head;

    if(!head) {
        return head;
    }

    p = head->next;

    while(p) {
        if(pPrev->val == p->val) {
            pPrev->next = p->next;
        }
        else {
            pPrev = p;
        }
        p = p->next;
    }

    return head;
}