栈程序演示(init,push,pop,clear,empty,traverse)

# include 
# include 
# include 

typedef struct Node
{
    int data;
    struct Node * pNext;
}NODE,* PNODE;

typedef struct Stack
{
    PNODE pTop;
    PNODE pBottom;
}STACK,* PSTACK;

void init(PSTACK ps);
void push(PSTACK ps,int val);
void traverse(PSTACK ps);
bool empty(PSTACK ps);
bool pop(PSTACK ps,int * val);
bool clear(PSTACK ps);



int main(void)
{
    STACK S;
    int val;
   
    init(&S);
    push(&S,1);
    push(&S,1);
    traverse(&S);
    if(clear(&S))
    {
        printf("chenggong!\n");
       
    }
    else
        printf("fail!\n");

   

    return 0;
}

void init(PSTACK ps)
{
    ps->pTop = (PNODE)malloc(sizeof(NODE));
    if(NULL == ps->pTop)
    {
        printf("分配失败！\n");
        exit(-1);
    }

    else
    {
        ps->pBottom = ps->pTop;
        ps->pBottom->pNext = NULL;
    }


    return;
   
}

void push(PSTACK ps,int val)
{
    PNODE pNew = (PNODE)malloc(sizeof(NODE));
    if(NULL == pNew)
    {
        printf("分配失败！\n");
        exit(-1);
    }
   
    pNew->data = val;
    pNew->pNext = ps->pTop;

    ps->pTop = pNew;

    return;

}

void traverse(PSTACK ps)
{
    PNODE p = ps->pTop;

    while(p != ps->pBottom)
    {
        printf("%d ", p->data);
        p = p->pNext;
    }
    printf("\n");

    return;
}

bool empty(PSTACK ps)
{
    if(ps->pTop == ps->pBottom)
    {
        return true;
    }
    else
    {
        return false;
    }
}

bool pop(PSTACK ps,int * val)
{
    if(empty(ps))
    {
        return false;
    }
    else
    {
        PNODE r = ps->pTop;
        *val = r->data;
        ps->pTop = r->pNext;
        free(r);

    }

    return true;

}

bool clear(PSTACK ps)
{
    if(empty(ps))
        return false;
    else
    {
        PNODE p = ps->pTop;
        PNODE q = NULL;

        while(p != ps->pBottom)
        {
            q = p->pNext;
            free(p);
            p = q;
        }

        ps->pTop = ps->pBottom;

        return true;
    }

}