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

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

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

void init(PSTACK pS) {
    pS->pTop = (PNODE)malloc(sizeof(NODE));
    if(NULL == pS->pTop) {
        printf("动态内存分配失败!\n");
        exit(-1);
    }
    else {
        pS->pBottom = pS->pTop;
        pS->pTop->pNext = NULL;
    }
}

void push(PSTACK pS, int val){
    PNODE pNew = (PNODE)malloc(sizeof(NODE));
    pNew->data = val;
    pNew->pNext = pS->pTop;
    pS->pTop = pNew;
}

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

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

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

void clear(PSTACK pS)
{
    if(empty(pS))
    {
        return;
    }
    else
    {
        PNODE p = pS->pTop;
        PNODE q = NULL;

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

}

int main(void)
{
    STACK S;
    int val;

    init(&S);
    push(&S, 1);
    push(&S, 2);
    push(&S, 3);
    push(&S, 4);
    push(&S, 5);
    push(&S, 6);
    traverse(&S);
    //clear(&S);   clear()清空栈
    if(pop(&S, &val))   //val用于保存出栈的数值
        printf("ok\n");
    else
        printf("error\n");

    traverse(&S);
    return 0;
}

代码整理自郝斌数据结构视频