剑指Offer-3.从尾到头打印链表(C++/Java)

//use stack
class Solution {
public:
    vector<int> printListFromTailToHead(ListNode* head) {
        stack<int> st;
        vector<int> res;
        while(head != nullptr){
            st.push(head->val);
            head = head->next;
        }
        while(!st.empty()){
            res.push_back(st.top());
            st.pop();
        }
        return res;
    }
};

//use reverse
import java.util.ArrayList;
import java.util.Collections;
public class Solution {
    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        ArrayList<Integer> res = new ArrayList<>();
        while(listNode != null){
            res.add(listNode.val);
            listNode = listNode.next;
        }
        Collections.reverse(res);
        return res;
    }
}