剑指offer 6.20

/**

• 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) {
ListNode pPre = null;
ListNode pCur = listNode;
ListNode pNext = null;
while(pCur != null){
pNext = pCur.next;
pCur.next = pPre;
pPre = pCur;
pCur = pNext;
}
ArrayList<Integer> result = new ArrayList<Integer>();
while(pPre!=null){
result.add(pPre.val);
pPre = pPre.next;
}
return result;

}

}