C代码实现栈

# include <stdio.h>
# include <malloc.h>
# include <stdlib.h>
//C语言实现栈 

//结点
typedef struct Node{
    int data;//数据
    struct Node* pNext;//指针 
}* PNODE,NODE; 

//栈 
typedef struct stack{
    PNODE pTop;
    PNODE pBottom;
}* PSTACK,STACK;

void init(PSTACK s);
void push(PSTACK s,int num);
bool isEmpty(PSTACK s) ;
bool pop(PSTACK s) ;
void traverse(PSTACK s);
void clear(PSTACK s) ;

int main(void)
{
    STACK s;
    init(&s);
    if(isEmpty(&s)){
        printf("栈为空\n");
    } 
    //压栈 
    push(&s,1);
    push(&s,4);
    push(&s,5);
    push(&s,77);
    push(&s,16);
    push(&s,11);
    push(&s,2);
    //遍历 
    traverse(&s);
    //出栈 
    if(pop(&s)){
        printf("出栈成功\n");
    }
    else{
        printf("出栈失败\n");
    }
    traverse(&s);
    clear(&s);
        if(isEmpty(&s)){
        printf("栈为空\n");
    } 
    return 0;
}

//初始化一个空栈
void init(PSTACK s)
{
    s->pTop = (PNODE)malloc(sizeof(NODE));
    //判断是否申请失败 
    if(NULL == s->pTop) {
        printf("内存申请失败");
        exit(-1);
    }
    s->pBottom = s->pTop;
    s->pBottom->pNext = NULL;
}

//压栈 
void push(PSTACK s,int num)
{
    //申请一个临时结点 
    PNODE tem = (PNODE)malloc(sizeof(NODE));
    tem->data = num;
    tem->pNext = s->pTop;
    s->pTop = tem; 
}

//判断栈是否为空
bool isEmpty(PSTACK s) 
{
    return s->pTop==s->pBottom;    
}

//出栈 
bool pop(PSTACK s) 
{
    if(isEmpty(s)){
        return false;
    }
    else{
        PNODE tem = s->pTop;
        s->pTop = tem->pNext;
        free(tem);
        tem = NULL;
        return true;
    }
}

//遍历栈
void traverse(PSTACK s)
{
    PNODE p = s->pTop;
    while(p!=s->pBottom){
        printf("%d ",p->data);
        p = p->pNext;
    }
    printf("\n");
}

//清空栈
void clear(PSTACK s) 
{
    if(isEmpty(s)){
        return;
    }
    
    PNODE p = s->pTop;
    PNODE q = NULL;
    while (p != s->pBottom){
        q = p->pNext;
        free(p);
        p = q;
    }
    s->pTop = s->pBottom;
}