链栈的实现

#ifndef  _LINKSTACK_H
#define _LINKSTACK_H

typedef int ElemType;
typedef int Status;

typedef struct linkStack
{
    ElemType data;
    struct linkStack * top;
}linkStack;

linkStack * CreateStack();
Status MakeEmpty();
int IsEmpty();
Status Push();
Status Pop();
ElemType Top();

#endif

/* linkstack.c */
#include <stdio.h>
#include <stdlib.h>
#include "linkstack.h"

linkStack * CreateStack()
{
    linkStack * S;
    S = (linkStack *)malloc(sizeof(linkStack));
    S -> top = NULL;
    MakeEmpty(S);
    return S;
}

Status MakeEmpty(linkStack * S)
{
    if(S == NULL)
    {
        return FALSE;
    }
    else
    {
        while(!IsEmpty(S))
            Pop(S);
    }
    return TRUE;
}

int IsEmpty(linkStack * S)
{
    return S -> top == NULL;
}

Status Push(linkStack * S, ElemType Data)
{
    linkStack * p;
    p = (linkStack *)malloc(sizeof(linkStack));
    p -> data = Data;
    p -> top = S -> top;
    S -> top = p;
    return TRUE;
}

Status Pop(linkStack * S)
{
    linkStack * p;
    if(IsEmpty(S))
        return FALSE;
    p = S -> top;
    S -> top = S -> top -> top;
    free(p);
    return TRUE;
}

ElemType Top(linkStack * S)
{
    return S -> top -> data;
}