#if !defined(LINKED_STACK_H_985552)
#define LINKED_STACK_H_985552
typedef int T; //数据元素类型
struct LNode {T data;LNode* next;
};struct LinkStack {LNode* top; // 栈顶指针int len; // 栈的长度
};LinkStack* LS_Create();
void LS_Free(LinkStack* ls);
void LS_MakeEmpty(LinkStack* ls);
bool LS_IsEmpty(LinkStack* ls);
int LS_Length(LinkStack* ls);
void LS_Push(LinkStack* ls, T x);
bool LS_Pop(LinkStack* ls, T& item);
bool LS_Top(LinkStack* ls, T& item);
void LS_Print(LinkStack* ls);
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "LnkStack.h"
#pragma warning(disable:4996)int main()
{LinkStack* ls=LS_Create();char dowhat[100];while(true) {scanf("%s", dowhat);if (!strcmp(dowhat,"push")) {T x;scanf("%d", &x);LS_Push(ls,x);}else if (!strcmp(dowhat,"pop")) {T item;LS_Pop(ls, item);}else {break;}}int length=LS_Length(ls);printf("Stack length: %d\n", length);LS_Print(ls);LS_Free(ls);
}

#include <stdio.h>
#include <stdlib.h>
#include "LnkStack.h"/*创建栈*/
LinkStack* LS_Create(){LinkStack* ls=(LinkStack*)malloc(sizeof(LinkStack));ls->top = NULL;ls->len = 0;return ls;
}
/*释放栈*/
void LS_Free(LinkStack* ls)
{LNode* curr = ls->top;while(curr) {LNode* next = curr->next;free(curr);curr=next;}free(ls);
}/*将栈变为空栈*/
void LS_MakeEmpty(LinkStack* ls)
{LNode* curr = ls->top;while(curr) {LNode* next = curr->next;free(curr);curr=next;}ls->top = NULL;ls->len = 0;
}/*判断栈是否为空*/
bool LS_IsEmpty(LinkStack* ls)
{// 请在这里补充代码，完成本关任务return ls->top==NULL?true:false;}/*获取栈的长度*/
int LS_Length(LinkStack* ls)
{// 请在这里补充代码，完成本关任务return ls->len;}/*将x进栈*/
void LS_Push(LinkStack* ls, T x)
{// 请在这里补充代码，完成本关任务LNode*link=(LNode*)malloc(sizeof(LNode));link->data=x;link->next=ls->top;ls->top=link;ls->len++;}/*出栈。出栈元素放入item；如果空栈，将返回false*/
bool LS_Pop(LinkStack* ls, T& item)
{// 请在这里补充代码，完成本关任务LNode*link=ls->top;if(LS_IsEmpty(ls)){return false;}item=ls->top->data;ls->top=link->next;free(link);ls->len--;return true;}/*读栈顶元素放入item。如果空栈，将返回false*/
bool LS_Top(LinkStack* ls, T& item)
{// 请在这里补充代码，完成本关任务if(LS_IsEmpty(ls)){return false;}item=ls->top->data;return true;}/*从栈顶到栈底打印各结点数据*/
void LS_Print(LinkStack* ls)
{if (ls->len==0){ printf("The stack: Empty!");return;}printf("The stack (from top to bottom):");LNode* curr=ls->top;while(curr) {printf(" %d", curr->data);curr=curr->next;}// printf("\n");
}