题解 | #从尾到头打印链表#

/**
*    public class ListNode {
*        int val;
*        ListNode next = null;
*
*        ListNode(int val) {
*            this.val = val;
*        }
*    }
*
*/
import java.util.ArrayList;
import java.util.Deque;
import java.util.LinkedList;
import java.util.List;
public class Solution {
    public ArrayList<Integer> printListFromTailToHead(ListNode head) {
        ListNode dummpHead = new ListNode(-1);
        dummpHead.next = head;
        ListNode cur = head;
        ArrayList<Integer> arrayList = new ArrayList<Integer>();
        Deque<Integer> deque = new LinkedList<Integer>();
        // while(cur!=null){
        //     ListNode next = cur.next;
        //     cur.next = next.next;
        //     next.next = cur;
        //     dummpHead.next = next;
        // }
        while (dummpHead.next != null) {
            deque.push(dummpHead.next.val);
            dummpHead.next = dummpHead.next.next;
        }
        while(!deque.isEmpty()){
         arrayList.add(deque.pop())  ;
        }
        return arrayList;
    }
}

从尾到头打印。

我们可以两种解法，一种就是反转链表，反转后，再遍历，一种就是用栈直接记录，然后在遍历栈