栈的链式存储结构,简称为链栈。
空栈就是top=null。
以下是c语言的实现
#include<stdio.h>
#include<stdlib.h>
#define MAXSIZE 5
#define ERROR 0
#define OK 1
typedef int SElemType;
typedef int Status;
//链栈的结构代码如下:
typedef struct StackNode {
SElemType data;
struct StackNode *next;
}StackNode, *LinkStackPtr;
typedef struct LinkStack {
LinkStackPtr top;
int count;
}LinkStack;
//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
S->top = s;//将新的结点s赋值给栈顶指针
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 (S->top == NULL) {//检测是否为空
return ERROR;
}
*e = S->top->data;
p = S->top;//将栈顶结点赋值给p
S->top = S->top->next;//使得栈顶指针下移一位,指向后一结点
free(p);//释放结点p
S->count--;
return OK;
}