链式栈

头文件

#define datatype int
struct stacknode
{
	int num;//编号
	datatype data;//数据
	struct stacknode *pNext;//指针域,指针域存放指向下一个结点的指针，以实现链表彻底线型结构
};

struct stacknode *init(struct stackonde *phead);//初始化
struct stacknode *push(struct stacknode *phead, int num, datatype data);//进栈
struct stacknode *pop(struct stacknode *phead, struct stacknode *poutdata);//出栈
struct stacknode *freeall(struct stacknode *phead);//释放
struct stacknode *printfall(struct stacknode *phead);//打印

源文件

#include"stacklinknode.h"
#include<stdio.h>
#include<stdlib.h>

struct stacknode *init(struct stackonde *phead)//初始化
{
	return NULL;
}

struct stacknode *push(struct stacknode *phead, int num, datatype data)//进栈
{
	struct stacknode *pnewnode = (struct stacknode*)malloc(sizeof(struct stacknode));//创建节点
	pnewnode->data = data;
	pnewnode->num = num;
	pnewnode->pNext = NULL;//开辟节点并赋值
	if (phead == NULL)
	{
		phead = pnewnode;
	}
	else
	{
		struct stacknode *p = phead;
		while (p->pNext != NULL)
		{
			p = p->pNext;
		}
		p->pNext = pnewnode;
	}
	return phead;
}

struct stacknode *printfall(struct stacknode *phead)//打印
{
	//递归
	if (phead == NULL)
	{
		return NULL;
	}
	else
	{
		printf("%d,%d,%p,%p\n", phead->data, phead->num, phead, phead->pNext);
		printfall(phead->pNext);
	}
}

struct stacknode *pop(struct stacknode *phead, struct stacknode *poutdata)//出栈
{
	if (phead == NULL)
	{
		return NULL;
	}
	else if (phead->pNext == NULL)
	{
		poutdata->data = phead->data;
		poutdata->num = phead->num;
		free(phead);
		phead = NULL;
		return phead;
	}
	else
	{
		struct stacknode *p = phead;
		while (p->pNext->pNext != NULL)
		{
			p = p->pNext;//循环到倒数第二个节点
		}
		poutdata->data = p->pNext->data;
		poutdata->num = p->pNext->num;
		free(p->pNext);
		p->pNext = NULL;
		return phead;
	}
}

struct stacknode *freeall(struct stacknode *phead)//释放
{
	if (phead == NULL)
	{
		return NULL;
	}
	else
	{
		struct stacknode *p1, *p2;
		p1 = phead;//头节点
		while (p1->pNext != NULL)
		{
			p2 = p1->pNext;//保存下一个节点
			p1->pNext = p2->pNext;//跳过p2
			free(p2);
		}
		free(phead);
		return NULL;
	}
}