include [HTML_REMOVED]

using namespace std;

//节点定义
struct Node{
int val;
Node * next;
}

//初始化
Node * init()
{
Node * dummy = new Node(-1);
return dummy;
}

//判断栈为空
bool empty(Node * dummy){
return dummy->next == NULL;
}

//入栈
void push(Node * dummy,int x){
Node * node = new Node(x);
node -> next = dummy -> next;
dummy -> next = node;
}

//出栈
void pop(Node * dummy){
dummy->next = dummy->next->next;
}

//读取栈顶元素
int top(Node * dummy){
return dummy->next->val;
}

int main()
{
// 测试链栈各操作
Node *dummy = init();
push(dummy, 1);
push(dummy, 2);
push(dummy, 3);
push(dummy, 4);

printf("栈顶元素：%d\n", top(dummy));

pop(dummy);

printf("栈顶元素：%d\n", top(dummy));

printf("栈是否为空：%d\n", empty(dummy));

print(dummy);

return 0;

}