题解 | #删除链表的倒数第n个节点#

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 * }
 */

public class Solution {
    /**
     * 
     * @param head ListNode类 
     * @param n int整型 
     * @return ListNode类
     */
    public ListNode removeNthFromEnd (ListNode head, int n) {
        // write code 
        ListNode fast = head;
        ListNode node = head;
        int l = 0;
        while(node != null){
            node = node.next;
            l++;
        }
        if(n == l){
            return head.next;
        }
        for(int i = 0;i <= n;i ++){
            fast = fast.next;
        }
        ListNode slow = head;
        while(fast != null){
            fast = fast.next;
            slow = slow.next;
        }
        slow.next = slow.next.next;
        return head;
    }
}