LintCode- 链表倒数第n个节点

链表倒数第n个节点

找到单链表倒数第n个节点，保证链表中节点的最少数量为n。

样例
给出链表 3->2->1->5->null和n = 2，返回倒数第二个节点的值1.

/** * Definition for ListNode. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int val) { *         this.val = val; *         this.next = null; *     } * } */ public class Solution {    /**     * @param head: The first node of linked list.     * @param n: An integer.     * @return: Nth to last node of a singly linked list.      */    ListNode nthToLast(ListNode head, int n) {            int count = 0;            ListNode re = head;            while(head != null){                count++;                head = head.next;            }            count = count - n;            while(count-- > 0){                re =re.next;            }            return re;        }}