顺序栈的定义和基本算法

//顺序栈的定义和基本算法
#include
#include
#define stacksize 100
typedef char datatype;

//定义顺序栈
typedef struct
{
    datatype data[stacksize];
    int top;
}seqstack;

//置空栈
seqstack *initstack(seqstack *s)
{
    s = (seqstack *)malloc(sizeof(seqstack));
    s->top = -1;
    return s;
}

//判断栈空
int stackempty(seqstack *s)
{
    if (s->top == -1)
        return 1;
    else
        return 0;
}

//判断栈满
int stackfull(seqstack *s)
{
    if (s->top == stacksize - 1)
        return 1;
    else
        return 0;
}

//进栈
int push(seqstack *s, int x)
{
    if (stackfull(s))
    {
        printf("error,stack overflow\n");
        return 0;
    }
    s->data[++s->top] = x;
    return 1;
}

//出栈
int pop(seqstack *s, int *x)
{
    if (stackempty(s))
    {
        printf("error,stack underflow\n");
        return 0;
    }
    *x = s->data[s->top];
    s->top--;
    return 1;
}

//取栈顶元素
int stacktop(seqstack *s)
{
    if (stackempty(s))
    {
        printf("error, stack is empty\n");
        return 0;
    }
    return (s->data[s->top]);
}