顺序栈

首先定义顺序栈的存储结构

/* 栈的顺序存储结构
**/
#define STACK_INIT_SIZE 100 //存储空间的初始分配量
#define STACK_INCREMENT 10  //存储空间的分配增量
typedef int SElemType;
typedef struct {
    SElemType *bottom;//栈底元素指针
    SElemType *top;   //栈顶元素指针
    int size;//栈空间最大容量
}SqStack;

顺序栈支持的基本操作如下：

#include "sqstack_algo.h"
#include <stdlib.h>

/*
** 初始化
*/
void SqStack_Init(SqStack *s)
{
    s->bottom = (SElemType*)malloc(STACK_INIT_SIZE * sizeof(SElemType));
    if (!s->bottom) exit(EXIT_FAILURE);
    s->top = s->bottom;//栈顶指针指向栈底(空栈)
    s->size = STACK_INIT_SIZE;
}

/*
** 清空
*/
void SqStack_Clear(SqStack *s)
{
    s->top = s->bottom;//栈顶指针指向栈底(空栈)
}

/*
** 销毁
*/
void SqStack_Destroy(SqStack *s)
{
    free(s->bottom);//释放栈空间
    s->top = s->bottom = NULL;
    s->size = 0;
}

/*
** 获取长度
*/
int SqStack_Length(SqStack s)
{
    return s.top - s.bottom;
}

/*
** 返回栈顶元素
*/
int SqStack_GetTop(SqStack s, SElemType *e)
{
    if (s.top > s.bottom){
        *e = *(--s.top);
        return 1;
    }
    return 0;
}

/*
** 入栈
*/
void SqStack_Push(SqStack *s, SElemType e)
{
    if (s->top - s->bottom == s->size){
        s->bottom = (SElemType*)realloc(s->bottom, 
            (s->size + STACK_INCREMENT)*sizeof(SElemType));
        if (!s->bottom) exit(EXIT_FAILURE);
        s->top = s->bottom + s->size;//修改栈顶指针,指向新的栈顶
        s->size += STACK_INCREMENT;//更新当前可用的最大容量
    }
    *(s->top)++ = e;//将e入栈，栈顶指针后移
}


/*
** 出栈
*/
int SqStack_Pop(SqStack *s, SElemType *e)
{
    if (s->top == s->bottom) return 0;//栈空
    *e = *(--s->top);
    return 1;
}

以下给出测试程序：

/*
** @brief This file is used for testing data structure and algorithms
** @data 2015-05-25
*/
#include <stdio.h>
#include "sqstack_algo.h"

int main(int argc, char **argv)
{
    SqStack s;
    SElemType e;

    SqStack_Init(&s);
    scanf("%d", &e);
    while (e > 0){
        SqStack_Push(&s, e);
        scanf("%d", &e);
    }

    while (SqStack_Pop(&s, &e)){
        printf("Pop: %d -> ", e);
        if (SqStack_GetTop(s, &e)){
            printf("Top: %d
", e);
        }else{
            printf("Top: NULL
");
        }
    }
    SqStack_Destroy(&s);//销毁

    return 0;
}