栈的应用

#include<stdio.h>
#include<stdlib.h>
typedef struct stack
{
    char date;
    struct stack *next;
}stacknode;

typedef struct
{
    stacknode *top;
}linkstack;/*栈顶指针*/

void init_stack(linkstack *s)/*初始化栈操作*/
{
    s->top=NULL;
}

int empty_stack(linkstack *s)
{
    return(s->top==NULL);
}

void push_stack(linkstack *s,char ch)
{
    stacknode *p;/*新建结点*/
    p=(stacknode *)malloc(sizeof(stacknode));
    p->next=s->top;/*如果是第一个结点，那么p->next为NULL*/
    p->date=ch;
    s->top=p;
}
char pop_stack(linkstack *s)
{
    stacknode *p;
    p=s->top;
    s->top=p->next;
    return p->date;
    
}

int main()
{
    linkstack s;
    char ch;
    init_stack(&s);
    while((ch=getchar())!='
')
    {
        push_stack(&s,ch);
    }
    while(!empty_stack(&s))
    {
        printf("%c",pop_stack(&s));
    
    }
}