题解 | 删除有序链表中重复的元素-I

/**
 * 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 ) {
    //思路
    //链表已经有序，依次遍历删除重复结点即可

    struct ListNode *headTmpPre = NULL;
    struct ListNode *headTmp = NULL;

    if (head == NULL || head->next == NULL) {
        return head;
    }

    headTmpPre = head;
    headTmp = head->next;
    while (headTmp) {
        if (headTmp->val == headTmpPre->val) {
		  // 当前结点与上一结点值相同，进行删除
            headTmpPre->next = headTmp->next;
        } else {
            headTmpPre = headTmpPre->next;
        }
        headTmp = headTmpPre->next;
    }
    return head;
}