2095.删除链表的中间节点.cpp

/*
 * @lc app=leetcode.cn id=2095 lang=cpp
 *
 * [2095] 删除链表的中间节点
 */

// @lc code=start
/**
 * 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 *deleteMiddle(ListNode *head)
    {
        if (head->next == nullptr)
        {
            return nullptr;
        }
        ListNode *fast = head;
        ListNode *slow = head;
        ListNode *pre = nullptr;
        while (fast && fast->next)
        {
            fast = fast->next->next;
            pre = slow;
            slow = slow->next;
        }
        pre->next = pre->next->next;

        return head;
    }
};
// @lc code=end