堆栈——链表实现

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <ctime> 

using namespace std;

using ElemType = int;

// 堆栈结构
class Node {
public:
	ElemType data;
	Node *next; 
};

// 初始化栈 
Node* initStack(Node *head, int n)
{
	srand(time(NULL));
	head->data=rand()%100 - 1;		// 栈底元素 
	while (n--) {
		Node *q = (Node*)malloc(sizeof(Node));
		q->data = rand()%100 - 1;
		q->next = head;
		head = q;
	}
	return head;
}

// 压栈 
Node* push(Node *head, ElemType val)
{
	Node *q = (Node*)malloc(sizeof(Node));
	q->data = val;
	q->next = head;
	head = q;
	return head;
}

// 出栈 
Node* pop(Node *head)
{
	Node *p = head;
	if (head->next == NULL) {
		free(p);
		return head;
	}
	head = head->next;
	free(p);
	return head;
}

void print(Node *head)
{
	Node *p = head;
	cout << "从栈顶到栈底的元素依次为：";
	while(p->next != NULL) {
		cout << p->data << " ";
		p = p->next;
	}
	cout << endl;
}

int main()
{
	Node *head = (Node*)malloc(sizeof(Node));		// 头指针指向栈顶 
	head->next = NULL;
	head = initStack(head, 10);
	print(head);
	head = push(head, 20);
	print(head);
	head = pop(head);
	print(head);
}