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
     */
    ListNode* removeNthFromEnd(ListNode* head, int n) {
        // write code here
        ListNode *fast, *slow, *prev,*cur,*next;
        int length = 0, i=0;
        slow = head;
        while(slow){
            length++;
            slow = slow->next;
        }
        if(length==n) return head->next;
        prev = nullptr;
        cur = head;
        next = head->next;
        slow = head;
        while(i++!=length-n){
            prev = cur;
            cur = next;
            next = next->next;
        }
        if(prev&&prev->next) prev->next = next;
        return head;
        
    }
};