数据结构：链栈

#include <iostream>
#include <stdlib.h>
using namespace std;

/**************************************************
*
*    链栈的结构
*
**************************************************/
typedef int SElemType;

typedef struct StackNode
{
    SElemType data;
    struct StackNode *next;

}StackNode, *StackNodePtr;

typedef struct LinkStack
{
    StackNodePtr top;
    int count;
}LinkStack;

/**************************************************
*
*    链栈的操作函数
*
**************************************************/
bool InitStack(LinkStack *s)
{
    cout << "Init Stack ..." << endl;
    s->top = NULL;
    s->count = 0;

    return true;
}
/*将栈清空*/
bool ClearStack(LinkStack *s)
{
    cout << "Clear Stack ..." << endl;
    if(s->top == NULL)
    {
        return true;
    }

    StackNodePtr p = s->top;
    StackNodePtr q = NULL;
    while(p)
    {
        q = p->next;
        free(p);
        p = q;
    }//while

    s->top = NULL;
    s->count = 0;

    return true;
}

/*判断栈是否为空*/
bool IsEmptyStack(LinkStack s)
{
    return s.count == 0;
}

/*返回栈的长度*/
int StackLength(LinkStack s)
{
    cout << "Stack Length: ";
    return s.count;
}

/*返回栈顶元素*/
bool GetTop(LinkStack s, SElemType *e)
{
    if(s.top == NULL)
    {
        return false;
    }

    *e = s.top->data;
    cout << "Get Top Item" << *e << endl;

    return true;
}

/*进栈*/
bool Push(LinkStack *s, SElemType e)
{
    cout << "Push Item " << e << endl;
    StackNodePtr p = (StackNodePtr)malloc(sizeof(StackNode));
    p->data = e;
    p->next = s->top;

    s->top = p;
    s->count++;
    
    return true;
}

/*出栈*/
bool Pop(LinkStack *s, SElemType *e)
{
    /*栈为空*/
    if(s->top == NULL)
    {
        return false;
    }
    StackNodePtr p = s->top;
    s->top = p->next;
    *e = p->data;
    free(p);

    s->count--;
    cout << "Pop Item " << *e << endl;

    return true;
}

/*输出栈元素*/
bool StackTraverse(LinkStack s)
{
    cout << "Stack Traverse ..." << endl;
    StackNodePtr p = s.top;
    while(p != NULL)
    {
        cout << p->data << ‘ ‘;
        p = p->next;
    }
    cout << endl;
    return true;
}

void main(void)
{
    LinkStack ls;
    InitStack(&ls);
    for(int i = 0; i < 5; i++)
    {
        Push(&ls, i);
    }
    StackTraverse(ls);
    int result;
    GetTop(ls, &result);
    Pop(&ls, &result);
    StackTraverse(ls);
    
    if(!IsEmptyStack(ls))
    {
        cout << StackLength(ls) << endl;
    }
    ClearStack(&ls);
    StackTraverse(ls);

    system("pause");
}