题解 | #输出单向链表中倒数第k个结点#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            // 构建链表
            ListNode listNode = new ListNode(-1);
            // 头结点
            ListNode first = listNode;
            for (int i = 0; i < n; i++) {
                int v = in.nextInt();
                ListNode next = new ListNode(v);
                listNode.next = next;
                listNode = next;
            }
            int k = in.nextInt();
            System.out.println(searchListNode(first, n -k + 1));
        }

    }

    public static int searchListNode(ListNode first, int k) {
        int t = 0;
        // 正向查找
        ListNode tn = first;
        for (int i = 0; i <= k; i++) {
            if (i == k) {
                t = tn.key;
            } else {
                tn = tn.next;
            }
        }

        return t;
    }
}
class ListNode {
    int key;
    ListNode next;


    ListNode(int key) {
        this.key = key;
        next = null;
    }
}