题解 | #删除链表峰值#

/**
 * struct ListNode {
 *  int val;
 *  struct ListNode *next;
 *  ListNode(int x) : val(x), next(nullptr) {}
 * };
 */
class Solution {
  public:
    /**
     * 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
     */
    ListNode* deleteNodes(ListNode* head) {
        // write code here
        if(!head) return head;
        ListNode* pre = head;
        ListNode* cur = head->next;
        if(!cur || !cur->next)return head;
	  //注意cur是否为空
        while (cur->next != NULL && cur) {
            if (pre->val < cur->val && cur->val > cur->next->val) {

                pre->next = cur->next;
                cur = cur->next;
            } else {
                pre = cur;
                cur = cur->next;
            }
        }
        return head;
    }
};