数据结构（栈的操作）C语言实现

# include<stdio.h>
# include<malloc.h>
# include<stdlib.h>

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

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

void initStack(PSTACK pS);
void pushStack(PSTACK pS,int val);
void traverseStack(PSTACK pS);
bool popStack(PSTACK pS,int *pVal);
bool empty(PSTACK pS);
void clearStack(PSTACK pS);

int main(void)
{
    STACK s;
    printf("%p
",s);
    int val;
    initStack(&s);//目的是造出一个空栈
    pushStack(&s,1);
    pushStack(&s,2);
    pushStack(&s,3);
    pushStack(&s,4);
    pushStack(&s,5);
    traverseStack(&s);

    if(popStack(&s,&val))
    {
        printf("出栈成功，出栈的元素是%d
",val);
    }
    else
    {
        printf("出栈失败
");
    }
    traverseStack(&s);
    clearStack(&s);
    traverseStack(&s);
    if(popStack(&s,&val))
    {
        printf("出栈成功，出栈的元素是%d
",val);
    }
    else
    {
        printf("出栈失败
");
    }

    return 0;
}
void initStack(PSTACK pS)
{
    pS->pTop=(PNODE)malloc(sizeof(NODE));
    if(pS->pTop==NULL)
    {
        printf("动态内存分配失败！
");
        exit(-1);
    }
    else
    {    
        pS->pBottm=pS->pTop;//pS->pBottm->pNext=pS->pTop->pNext ?
        pS->pTop->pNext=NULL;
    }
}
void pushStack(PSTACK pS,int val)
{
    PNODE pNew=(PNODE)malloc(sizeof(NODE));
    pNew->data=val;
    pNew->pNext=pS->pTop;//因为刚开始pTop和pBottom指向的都是同一个节点，所以pS->pTop=pS->pBottom
    pS->pTop=pNew;
    
    return;
}
void traverseStack(PSTACK pS)
{
    PNODE p=pS->pTop;
    while(p !=pS->pBottm)
    {
        printf("%d ",p->data);
        p=p->pNext;
    }
    printf("
");
    return;
}
bool empty(PSTACK pS)
{
    if(pS->pTop==pS->pBottm)
        return true;
    else
        return false;
}
//把pS指向的栈出栈一次，并将出栈的元素存入pVal形参所指向的变量中，如果出栈失败，返回false，否则返回true
bool popStack(PSTACK pS,int *pVal)
{
    if(empty(pS))//pS本身存放的就是s的地址
    {
        return false;
    }
    else
    {
        PNODE r=pS->pTop;//目的是为了释放那一块内存
        *pVal=r->data;
        pS->pTop=r->pNext;
        free(r);
        r=NULL;

        return true;
    }
}
//清空
void clearStack(PSTACK pS)
{
    if(empty(pS))
    {
        return;
    }
    else
    {
        PNODE p=pS->pTop;
        PNODE q=NULL;
        while(p !=pS->pBottm)
        {
            q=p->pNext;
            free(p);
            p=q;
        }
        pS->pTop=pS->pBottm;
    }
}