#include "stdio.h"    #include "stdlib.h"   #include "io.h"  #include "math.h"  #include "time.h"#define OK 1#define ERROR 0#define TRUE 1#define FALSE 0#define MAXSIZE 20 /* 存储空间初始分配量 */typedef int Status; typedef int SElemType; /* SElemType类型根据实际情况而定，这里假设为int *//* 链栈结构 */typedef struct StackNode{        SElemType data;        struct StackNode *next;}StackNode,*LinkStackPtr;typedef struct{        LinkStackPtr top;        int count;}LinkStack;Status visit(SElemType c){        printf("%d ",c);        return OK;}/*  构造一个空栈S */Status InitStack(LinkStack *S){         S->top = (LinkStackPtr)malloc(sizeof(StackNode));        if(!S->top)                return ERROR;        S->top=NULL;        S->count=0;        return OK;}/* 把S置为空栈 */Status ClearStack(LinkStack *S){         LinkStackPtr p,q;        p=S->top;        while(p)        {                  q=p;                p=p->next;                free(q);        }         S->count=0;        return OK;}/* 若栈S为空栈，则返回TRUE，否则返回FALSE */Status StackEmpty(LinkStack S){         if (S.count==0)                return TRUE;        else                return FALSE;}/* 返回S的元素个数，即栈的长度 */int StackLength(LinkStack S){         return S.count;}/* 若栈不空，则用e返回S的栈顶元素，并返回OK；否则返回ERROR */Status GetTop(LinkStack S,SElemType *e){        if (S.top==NULL)                return ERROR;        else                *e=S.top->data;        return OK;}/* 插入元素e为新的栈顶元素 */Status Push(LinkStack *S,SElemType e){        LinkStackPtr s=(LinkStackPtr)malloc(sizeof(StackNode));         s->data=e;         s->next=S->top;    /* 把当前的栈顶元素赋值给新结点的直接后继，见图中① */        S->top=s;         /* 将新的结点s赋值给栈顶指针，见图中② */        S->count++;        return OK;}/* 若栈不空，则删除S的栈顶元素，用e返回其值，并返回OK；否则返回ERROR */Status Pop(LinkStack *S,SElemType *e){         LinkStackPtr p;        if(StackEmpty(*S))                return ERROR;        *e=S->top->data;        p=S->top;                    /* 将栈顶结点赋值给p，见图中③ */        S->top=S->top->next;    /* 使得栈顶指针下移一位，指向后一结点，见图中④ */        free(p);                    /* 释放结点p */                S->count--;        return OK;}Status StackTraverse(LinkStack S){        LinkStackPtr p;        p=S.top;        while(p)        {                 visit(p->data);                 p=p->next;        }        printf("\n");        return OK;}int main(){        int j;        LinkStack s;        int e;        if(InitStack(&s)==OK)                for(j=1;j<=10;j++)                        Push(&s,j);        printf("栈中元素依次为：");        StackTraverse(s);        Pop(&s,&e);        printf("弹出的栈顶元素 e=%d\n",e);        printf("栈空否：%d(1:空 0:否)\n",StackEmpty(s));        GetTop(s,&e);        printf("栈顶元素 e=%d 栈的长度为%d\n",e,StackLength(s));        ClearStack(&s);        printf("清空栈后，栈空否：%d(1:空 0:否)\n",StackEmpty(s));        return 0;}