链栈的实现

stack.h

#ifndef _STACK_H
#define _STACK_H

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

typedef struct StackNode
{
    int data;
    struct StackNode* next;
}StackNode,*LinkStack;

//初始化
void init(LinkStack top);
//判断栈是否为空
int isEmpty(LinkStack top);
//将一个元素压入栈
int push(LinkStack top, int val);
//从栈中弹出一个元素
int pop(LinkStack top, int *val);
//获取栈顶元素的值
int getTop(LinkStack top);


#endif

stack.c

#include "stack.h"

void init(LinkStack top)
{
    top->next = NULL;
}

int isEmpty(LinkStack top)
{
    if(top->next == NULL)
        return 1;
    return 0;
}
//top指向的结点为空的头结点
int push(LinkStack top, int val)
{
    StackNode *newNode;
    newNode = (StackNode*)calloc(1,sizeof(StackNode));
    newNode->data = val;

    if(newNode == NULL)
        return 0;
    newNode->next = top->next;
    top->next = newNode;
    return 1;
}


int pop(LinkStack top, int *val)
{
    StackNode *oldNode;
    if(isEmpty(top))
    {
        printf("The stack is empty!
");
        return 0;
    }
    oldNode = top->next;
    //记录栈顶元素的值
    *val = oldNode->data;
    top->next = oldNode->next;
    //释放
    free(oldNode);
    return 1;
}

int getTop(LinkStack top)
{
    return top->next->data;
}

main.c

#include "stack.h"

int main()
{
    LinkStack top;
    top = (StackNode*)malloc(sizeof(StackNode));
    int val, index;
    init(top);

    //向栈中压入一系列元素
    for(index = 0; index < 12; index++)
        push(top,index);

    //获取栈顶元素
    val = getTop(top);
    printf("栈顶元素为：%d
",val);


    //弹出栈中元素
    printf("依次弹出栈顶元素:
");
    while(!(isEmpty(top)))
    {
        pop(top,&val);
        printf("->%2d",val);
    }
    printf("
");
    return 0;
}

 运行结果：