剑指offer面试题6: 从头到尾打印链表

1. 用栈

#include <iostream>
#include <stack>
using namespace std;


struct ListNode {
    int val;
    ListNode *next;
    ListNode(int x) : val(x), next(NULL) {}
};

class Solution {
public:
    void PrintListReversingly(ListNode* head) {
        stack<ListNode*> nodes;
        
        ListNode *pNode = head;
        while (pNode != nullptr)
        {
            nodes.push(pNode);
            pNode = pNode->next;
        }
        
        while (!nodes.empty())
        {
            pNode = nodes.top();
            cout << pNode->val << "\t";
            nodes.pop();    
        }        
    }
};
void test_data()
{
        ListNode *head = new ListNode(0);
        ListNode *p ;
        p = head;
        Solution s;
        int n = 0;
        int T = 5;
        while (T-- && cin >> n)
        {
            ListNode *q;
            q = new ListNode(n);
            p->next = q;
            p = q;        
        }
        p->next = NULL;
        
        head = head->next;
        s.PrintListReversingly(head);
}
int main()
{
    test_data();
    return 0;
    
}