解释:
由于链表有头指针,而栈也必须有头指针,所有合二为一
链栈为空的条件为头指针为空,头指针存储在一个新的结构体中。
#include <iostream>
using namespace std;
#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 SElemType;
typedef int Status;
typedef struct StackNode
{
SElemType data;
struct StackNode * next;
}StackNode,*LinkStackPtr;
typedef struct
{
LinkStackPtr top;
int count;
}LinkStack; //如果只需要 stu1、stu2 两个变量,后面不需要再使用结构体
//名定义其他变量,那么在定义时也可以不给出结构体名
Status init_List(LinkStack * link){
link->top = (LinkStackPtr)malloc(sizeof(LinkStack));
if(link->top==NULL){
return ERROR;
}else{
link->count = 0; //链栈为空的条件为指向链栈的头指针为NULL,
//即栈顶指针为空,链栈没有头结点,栈顶指针和
link->top = NULL; //头指针为同一个
return OK;
}
}
Status Push(LinkStack *S,SElemType e){
LinkStackPtr s = (LinkStackPtr)malloc(sizeof(StackNode));
s->data = e;
s->next = S->top; //栈结构只能在栈顶操作,增加新元素的Next指向
//原来的栈顶元素
S->top = s ; //成为新的栈顶元素
S->count++;
}
Status isEmpty(LinkStack link){
if(link.top == NULL)
return TRUE;
else
return FALSE;
}
Status Pop(LinkStack *S,SElemType *e){
if(isEmpty(*S))
return ERROR;
*e = S->top->data;
LinkStackPtr s = S->top;
S->top = S->top->next;
free(s);
S->count--;
}
int ListLength(LinkStack s){
if(isEmpty(s))
return FALSE;
return s.count;
}
Status Get_Top(LinkStack s, SElemType *e){
if(isEmpty(s))
return FALSE;
*e = s.top->data;
return OK;
}
Status ClearStack(LinkStack *s){
if(isEmpty(*s))
return FALSE;
LinkStackPtr p = s->top;
LinkStackPtr q;
while(p){
q = p->next;
free(p);
p = q;
}
s->count = 0;
s->top = NULL;
}
int main()
{
LinkStack s;
printf("链栈是否初始化成功%d\n",init_List(&s));
Push(&s,3);
Push(&s,2);
Push(&s,1);
LinkStackPtr p = s.top;
printf("从栈顶开始\n");
while(p){
printf("%d\n",p->data);
p = p->next;
}
int result;
p = s.top;
while(p){
Pop(&s,&result);
printf("删除的元素依次为%d\n",result);
p = s.top;
}
Push(&s,3);
Push(&s,2);
Push(&s,1);
Push(&s,3);
Push(&s,2);
Push(&s,1);
printf("链表的长度为%d\n",ListLength(s));
int value;
printf("取回栈顶的值%d\n",Get_Top(s,&value));
ClearStack(&s);
printf("清空栈后,栈空否:%d(1:空 0:否)\n",isEmpty(s));
return 0;
}