劍指offer---鏈表值從尾到頭的順序返回一個ArrayList

輸入一個鏈表，按鏈表值從尾到頭的順序返回一個ArrayList。

1、使用棧來緩存鏈表的數據

/**
*  struct ListNode {
*        int val;
*        struct ListNode *next;
*        ListNode(int x) :
*              val(x), next(NULL) {
*        }
*  };
*/
class Solution {
public:
    vector<int> printListFromTailToHead(ListNode* head) {
        vector<int> ArrayList;
        stack<int> st;
        ListNode *p = head;
        int tmp;
        while(p)
        {
            tmp = p->val;
            st.push(tmp);
            p = p->next;
        }

        while(!st.empty())
        {
            tmp = st.top();
            ArrayList.push_back(tmp);
            st.pop();
        }
        return ArrayList;
    }
};

2、不緩存數據，先存在容器中，然後調用reverse方法反轉

/**
*  struct ListNode {
*        int val;
*        struct ListNode *next;
*        ListNode(int x) :
*              val(x), next(NULL) {
*        }
*  };
*/
class Solution {
public:
    vector<int> printListFromTailToHead(ListNode* head) {
        vector<int> ArrayList;
        stack<int> st;
        ListNode *p = head;
        int tmp = 0;
        while(p != NULL)
        {
            tmp = p->val;
            ArrayList.push_back(tmp);
            p = p->next;
        }

        reverse(ArrayList.begin(), ArrayList.end());
        return ArrayList;
    }
};