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
        //先是查找倒数第n个结点在什么位置
        ListNode * res = new ListNode(-1);
        res->next = head;
        ListNode* cur = head;
        ListNode* pre = res;
        ListNode* fast = head;
        while(n--)
        fast = fast->next;
        while(fast)
        {
            fast = fast->next;
            pre = cur;
            cur = cur->next;
        }
        pre->next = cur->next;
        free(cur);
        return res->next;
    }
};

注意看题目条件啊笨蛋！