题解 | #删除链表的倒数第n个节点#

 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */

class Solution {
public:
    /**
     * 
     * @param head ListNode类 
     * @param n int整型 
     * @return ListNode类
     */
    typedef struct ListNode* Node;
    ListNode* removeNthFromEnd(ListNode* head, int n) {
        if(!head) return head;
        Node fast=head;
        Node slow=head;
        Node pre=nullptr;
        for(int i=0;i<n;i++)
        {
            fast=fast->next;
        }
        if(!fast) return head->next;
        while(fast)
        {
            pre=slow;
            fast=fast->next;
            slow=slow->next;
        }
        pre->next=slow->next;
        return head;
    }
};