链栈（头插法）

#include "stdio.h"
#include "malloc.h"

typedef int ElemType;

typedef struct node{
    ElemType data;
    struct node *next;
}LinkStack;

LinkStack * InitStack(){
    LinkStack *s;
    s=(LinkStack *)malloc(sizeof(LinkStack));
    if(s!=NULL){
        s->next = NULL;
        return s;
    }else{
        printf("分配内存失败！");
        return NULL;
    }
}
void ClearStack(LinkStack *s){
    LinkStack *p=s->next;
    while(p!=NULL){
        free(s);
        s=p;
        p=p->next;
    }
    free(s);
}
int StackLength(LinkStack *s){
    int i=0;
    LinkStack *p;
    p=s->next;
    while(p!=NULL){
        i++;
        p=p->next;
    }
    return i;
}
int IsEmpty(LinkStack *s){
    return s->next==NULL;
}
void Push(LinkStack *s,ElemType e){
    LinkStack *p;
    p=(LinkStack *)malloc(sizeof(LinkStack));
    p->data=e;
    p->next=s->next;//向下牵手
    s->next=p;//向上牵手

}
//出栈
ElemType Pop(LinkStack *s){
    ElemType e;
    LinkStack *p;
    if(IsEmpty(s)){//空的
        return 0;
    }
    p=s->next;//寄存头后的节点位置
    e=p->data;//取走数据
    s->next = p->next;//牵下一个下一个
    free(p);//释放掉p
    return e;
}
ElemType GetTop(LinkStack *s){
    ElemType e;
    if(IsEmpty(s)){
        return 0;
    }
    e=s->next->data;//直接取值
    return e;
}

void DispStack(LinkStack *s){
    LinkStack *p=s->next;//第一次指向栈顶
    while(p!=NULL){//不等于0就输出
        printf("%d\t",p->data);
        p=p->next;
    }
    printf("\n");
}

main(){
    int i;
    LinkStack *s;
    s=InitStack();
    for(i=0;i<10;i++){
        Push(s,i+1);
    }
    //ClearStack(s);
    printf("栈的长度为：%d\n",StackLength(s));
    /*
    for(i=0;i<10;i++){
        printf("%d\t",Pop(s));
    }
    */
    DispStack(s);
    printf("\n");
    printf("栈的长度为：%d\n",StackLength(s));

}