问题描述

关于栈的链式结构，请问以下代码问题在哪？

#include
#include
struct node
{
int data;
struct node next;
};
struct node *createemptystack_link(void)
{
struct node *top;
top=(struct node)malloc(sizeof(struct node));
if(top!=NULL)
top->next=NULL;
else
printf("out of space!");
return top;
}
int isemptystack_link(struct node top)
{
return (top==NULL);
}
void push_link(struct node *top,int x)
{
struct node *p;
p=(struct node)malloc(sizeof(struct node));
if(p==NULL)
printf("out of space!");
else
{
p->data=x;
p->next=top;
top=p;
}
}
void pop_link(struct node *top)
{
struct node *p;
if(top==NULL)
printf("empty stack pop!");
else
{
p=top;
top=top->next;
free(p);
}
}
int main()
{
struct node *createemptystack_link(void);
void push_link(struct node *top,int x);
void pop_link(struct node *top);
int isemptystack_link(struct node *top);
int i,n,x;
struct node *p;
p=createemptystack_link();
printf("请输入入栈数据的个数：");
scanf("%d",&n);
printf("请输入数据：");
for(i=0;i
{
scanf("%d",&x);
push_link(p,x);
}
while(p)
{
printf("%d",p->data);
pop_link(p);
}
return 0;
}
从测试各函数来看，是创建链表或入栈地方有错。

解决方案

用VS2013编译通过

 // ConsoleApplication1.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

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

struct node
{
    int data;
    struct node *pre;
    struct node *next;
};

struct node *p = NULL;

int isemptystack_link()
{
    return p->pre == NULL;
}

void push_link(int x)
{
    if (p == NULL)
    {
        p = (struct node*)malloc(sizeof(struct node));
        p->data = x;
        p->pre = NULL;
        p->next = NULL;
    }
    else
    {
        struct node *pp = p;
        p = (struct node*)malloc(sizeof(struct node));
        p->data = x;
        p->pre = pp;
        pp->next = p;
        p->next = NULL;
    }
}
void pop_link()
{
    if (p == NULL)
        printf("empty stack pop!");
    else
    {
        p = p->pre;
        if (p != NULL)
            free(p->next);
    }
}

int _tmain(int argc, _TCHAR* argv[])
{
    int i, n, x;
    printf("num");
    scanf_s("%d", &n);
    printf("data");
    for (i = 0; i<n; i++)
    {
        scanf_s("%d", &x);
        push_link(x);
    }
    while (p != NULL)
    {
        printf("%dn", p->data);
        pop_link();
    }
    return 0;
}

解决方案二：

你的代码错得太多，你没有指向前继节点的指针，怎么能出栈呢？

解决方案三：

struct node
{
int data;
struct node next; //此处应该用指针类型
};

p=(struct node)malloc(sizeof(struct node));//强制转换应该转换为指针类型

int isemptystack_link(struct node top) //判断栈是否为空，应该是判断top->next==NULL
{
return (top==NULL);
}

p=(struct node)malloc(sizeof(struct node)); //同上

p->data=x;
p->next=top; //节点插入出错，链表的头部插入应该是插到头结点的后方
top=p;

应该改为 p->next = top->next; top->next = p;

if(top==NULL) //同上

p=top;
top=top->next;
free(p); //改为p = top->next;top->next = top->next->next;free(p);

错误太多，目测对链栈的理解太浅，多读读书在实践吧！