题目描述:
示例:
思路:
初始化两个指针before,after指向链表头节点,before先走k个节点,然后再让before,after同时前进,当before走到链表末尾时,after所在位置就是倒数第k个节点。
代码实现:
class Solution {
public ListNode getKthFromEnd(ListNode head, int k) {
ListNode before = head, after = head;
while (k-- > 0) { // before先前进k个节点
before = before.next;
}
while (before != null) { // before,after指针同时前进,直到before走出链表边界
before = before.next;
after = after.next;
}
return after;
}
}