数据结构与算法（6）链栈

本博客中使用单链表完成栈的构建

栈结构

typedef char Elemtype;

typedef struct Node{
    Elemtype data;
    struct Node *next;
}StackNode, *LinkStack;

栈的各种运算实现与测试代码

#include <stdio.h>
#include <stdlib.h>

#define OK 1
#define ERROR 0

#define TRUE 1
#define FALSE 0

typedef int Status;
typedef char Elemtype;

typedef struct Node{
    Elemtype data;
    struct Node *next;
}StackNode, *LinkStack;

/*
链栈的初始化
*/
Status InitStack(LinkStack *s)
{
    (*s) = (LinkStack)malloc(sizeof(StackNode));
    (*s)->next = NULL;
    return OK;
}
/*
销毁链表
*/
Status DestoryStack(LinkStack *s)
{
    LinkStack p;
    while (*s){
        p = (*s)->next;
        free(*s);
        (*s) = p;
    }
    return OK;
}
/*
栈空检测
*/
Status EmptyStack(LinkStack s)
{
    if (s->next == NULL)
        return TRUE;
    else
        return FALSE;
}
/*
压栈
*/
Status Push(LinkStack *s, Elemtype e)
{
    LinkStack new_node;                 
    new_node = (LinkStack)malloc(sizeof(StackNode));
    if (!new_node)
        return ERROR;
    new_node->data = e;

    //新结点作为首元结点
    new_node->next = (*s)->next;
    (*s)->next = new_node;

    return OK;
}
/*
弹栈
*/
Status Pop(LinkStack *s, Elemtype *e)
{
    LinkStack p;
    //注意在弹栈的时候要进行非空检测
    if (EmptyStack(s))
        return ERROR;
    p = (*s)->next; //指向首元结点

    *e = p->data;
    (*s)->next = p->next;
    free(p);

    return OK;
}
/*
显示栈中数据内容
*/
Status DispStack(LinkStack s)
{
    LinkStack p;
    if (EmptyStack(s))
        return ERROR;

    p = s->next;
    while (p){
        printf("%c ", p->data);
        p = p->next;
    }
    printf("\n");

    return OK;
}
/*
显示栈顶数据内容
*/
Elemtype GetTop(LinkStack s)
{
    if (EmptyStack(s))
        return ERROR;
    else
        return s->next->data;
}



int main()
{
    LinkStack s;
    Elemtype e;
    printf("初始化链栈\n");
    InitStack(&s);  //初始化s为头结点指针
    printf("压栈\n");
    Push(&s, 'a');
    Push(&s, 'b');
    Push(&s, 'c');
    Push(&s, 'd');
    Push(&s, 'e');
    Push(&s, 'f');
    Push(&s, 'g');
    Push(&s, 'h');
    printf("显示栈数据元素\n");
    DispStack(s);
    Pop(&s, &e);
    printf("弹栈操作 %c\n", e);
    Pop(&s, &e);
    printf("弹栈操作 %c\n", e);
    Pop(&s, &e);
    printf("弹栈操作 %c\n", e);
    printf("显示栈数据元素\n");
    DispStack(s);
    printf("栈顶内容 %c\n", GetTop(s));


    printf("销毁链栈\n");
    DestoryStack(&s);

    system("pause");
    return 0;
}