使用链式栈，实现十进制转八进制：键盘输入一个十进制数，经过链式栈的相关算法，输出八进制数

#include <stdio.h>
//链式栈节点
typedef struct node
{
    //数据域
    int data;
    struct node *next;
} Node;
//链式栈管理结构体
typedef struct linkStack
{
    int size;
    Node *top;
} Linkstack;
//初始化空栈
Linkstack *Initstack()
{
    Linkstack *s = (Linkstack *)malloc(sizeof(Linkstack));
    if (s != NULL)
    {
        s->top = NULL;
        s->size = 0;
    }
    return s;
}
//判断栈是否为空
int ifNULL(Linkstack *s)
{
    if (s->size == 0)
        return 1;
    else return 0;
}
//取栈顶元素
int top(Linkstack *s, int *p)
{
    if (ifNULL(s))
        return 0;
    *p = s->top->data;
    return 1;
}
//出栈
int Pop(Linkstack *s)
{
    if (ifNULL(s))
        return 0;
    //取栈顶元素的地址
    Node *pm = s->top;
    //将原栈顶元素剔除出栈
    s->top = pm->next;
    //pm->next = NULL;
    //*p = pm->data;
    free(pm);
    return 1;
}
//入栈
int Push(Linkstack *s, int data)
{
    Node *new = (Node *)malloc(sizeof(Node));
    if (new != NULL)
    {
        new->data = data;
        new->next = s->top;
        s->top = new;
        s->size++;
        return 1;
    }  
}
int main()
{
    int a, tmp, data;
    Linkstack *s = Initstack();
    printf("输入十进制整数：");
    scanf("%d", &a);
    while (a)
    {
        tmp = a % 8;
        Push(s, tmp);
        a = a / 8;
    }
    printf("八进制数：");
    while(!ifNULL(s))
    {
        printf("%d", s->top->data);
        Pop(s); 
    }
    return 0;
}