动态顺序栈

//顺序栈的结构定义
typedef int STDataType;
typedef struct Stack {
  STDataType* a;
  int top;
  int capacity;
}ST;

//顺序栈的初始化
void STInit(ST* pst)
{
  assert(pst);
  pst->a = NULL;
  pst->top = 0;//top指针指向栈顶元素的下一位
  pst->capacity = 0;//顺序栈的容量
}

//顺序栈的打印
void STPrint(ST pst)
{
  for (int i = 0; i < pst.top; i++)
  {
    printf("%d ", pst.a[i]);
  }
  printf("\n");
}

//顺序栈的入栈
void STPush(ST* pst, STDataType x)
{
  assert(pst);
  //检查扩容
  if (pst->top == pst->capacity)
  {
    int newcapacity = pst->capacity == 0 ? 4 : 2 * pst->capacity;
    STDataType* p = (STDataType*)realloc(pst->a, newcapacity * sizeof(STDataType));
    if (p == NULL)
    {
      perror("realloc fail");
      exit(-1);
    }
    else
    {
      pst->a = p;
      pst->capacity = newcapacity;
    }
  }
  pst->a[pst->top++] = x;
}

//顺序栈出栈
void STPop(ST* pst)
{
  assert(pst);
  assert(pst->top > 0);
  pst->top--;
}

//求顺序栈栈顶元素
STDataType STTop(ST* pst)
{
  assert(pst);
  assert(pst->top > 0);
  return pst->a[pst->top - 1];
}

//顺序栈判空
bool STEmpty(ST* pst)
{
  assert(pst);
  return pst->top == 0;
}

//顺序栈销毁
void STDestroy(ST* pst)
{
  assert(pst);
  if (pst->a != NULL)
  {
    free(pst->a);
    pst->a = NULL;
    pst->top = 0;
    pst->capacity = 0;
  }
}

void test01()
{
    //定义顺序栈
    ST st;
    //初始化顺序栈
    STInit(&st);
    //顺序栈入栈
    STPush(&st, 1);
    STPush(&st, 2);
    STPush(&st, 3);
    STPush(&st, 4);
    STPush(&st, 5);
    //顺序栈打印
    STPrint(st);
    //顺序栈出栈
    STPop(&st);
    STPop(&st);
    STPop(&st);
    //顺序栈打印
    STPrint(st);
    //打印栈顶元素
    printf("%d\n", STTop(&st));
    //顺序栈判空
    if (STEmpty(&st))
        printf("空\n");
    else
        printf("非空\n");
    //顺序栈出栈
    STPop(&st);
    STPop(&st);
    //顺序栈判空
    if (STEmpty(&st))
        printf("空\n");
    else
        printf("非空\n");
    //顺序栈销毁
    STDestroy(&st);
}
int main()
{
    test01();
    return 0;
}