剑指offer22. 链表中倒数第k个节点

用双指针可以解决

public class Solution {
    public ListNode getKthFromEnd(ListNode head, int k) {
        ListNode temp = head;
        while(temp!=null){
            if(k<=0){
                head = head.next;
            }
            temp = temp.next;
            k--;
        }
        return head;
    }
}

普通遍历

class Solution {
    public ListNode getKthFromEnd(ListNode head, int k) {
        ListNode temp = head;
        ArrayList<ListNode>al = new ArrayList<ListNode>();
        while(temp!=null){
            al.add(temp);
            temp = temp.next;
        }
        return al.get(al.size()-k);
    }
}