remove_nodes_from_linked_list.cpp

// 从链表中移除节点
// https://leetcode.cn/problems/remove-nodes-from-linked-list
// INLINE  ../../images/stack/remove_nodes_from_linked_list.jpeg

#include <headers.hpp>

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode() : val(0), next(nullptr) {}
 *     ListNode(int x) : val(x), next(nullptr) {}
 *     ListNode(int x, ListNode *next) : val(x), next(next) {}
 * };
 */
class Solution {
public:
  ListNode *removeNodes(ListNode *head) {
    if (head == nullptr) {
      return nullptr;
    }
    head->next = removeNodes(head->next);
    if (head->next != nullptr && head->val < head->next->val) {
      return head->next;
    } else {
      return head;
    }
  }
};