Sword *offer -- reverse order of linked list

Enter a linked list , Return a list from the end to the end ArrayList.

There are many ways , Because I am not familiar with the linked list, I focused on the reverse order of the linked list , Other relatively simple methods are Stack（ Why didn't I expect ！）, Recursion and placement ArrayList Then recycle in reverse order .

Reverse order of linked list

Highlight ！** First, let p==null; In order to connect the tail of the linked list null
Be careful temp = q.next The location of , Be sure to put it in the first sentence .

/** * public class ListNode { * int val; * ListNode next = null; * * ListNode(int val) { * this.val = val; * } * } * */
import java.util.ArrayList;
public class Solution {
    
    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
    
        ArrayList<Integer> array = new ArrayList<>();

        if(listNode == null ){
    
            return array;
        }
        if(listNode.next==null){
    
             array.add(listNode.val);
            return array;
        }
       

        ListNode p = null;
        ListNode q = listNode;
        ListNode temp = q.next;
        while(q != null){
    
            temp = q.next;
            q.next = p;
  
            p = q;
            q = temp;
        }
        while(p!=null){
    
            array.add(p.val);
            p=p.next;
        }
        return array;
    }
}