/*  file name : stack.c     */
/* 使用堆棧處理數(shù)據(jù)--新增、刪除、輸出 */

#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#define MAX 100
void push_f(void);   /* 新增函數(shù) */
void pop_f(void);    /* 刪除函數(shù)*/
void list_f(void);   /* 輸出函數(shù) */

char item[MAX][20];
int top = -1;

void main(void)
{
	char option;
	while(1)
	{
		printf("\n *****************************\n");
		printf("        <1> insert (push)\n");
		printf("        <2> delete (pop)\n");
		printf("        <3> list\n");
		printf("        <4> quit\n");
		printf(" *****************************\n");
		printf(" Please enter your choice...");
		option = getche();
		switch(option)
		{
			case '1':
				push_f();
				break;
			case '2':
				pop_f();
				break;
			case '3':
				list_f();
				break;
			case '4':
				exit(0);
		}
	}
}

void push_f(void)
{
	if(top >= MAX-1)   /* 當(dāng)堆棧已滿，則顯示錯(cuò)誤 */
		printf("\n\nStack is full !\n");
	else
	{
		top++;
		printf("\n\n Please enter item to insert: ");
		gets(item[top]);
	}
}

void pop_f(void)
{
	if(top < 0)   /* 當(dāng)堆棧沒有數(shù)據(jù)存在，顯示錯(cuò)誤 */
		printf("\n\n No item, stack is empty !\n");
	else
	{
		printf("\n\n Item %s deleted\n", item[top]);
		top--;
	}
}

void list_f(void)
{
	int count = 0, i;
	if(top < 0)
		printf("\n\n No item, stack is empty\n");
	else
	{
		printf("\n\n  ITEM\n");
		printf(" ------------------\n");
		for(i = 0; i <= top; i++)
		{
			printf("  %-20s\n", item[i]);
			count++;
			if(count % 20 == 0) getch();
		}
		printf(" ------------------\n");
		printf("  Total item: %d\n", count);
		getch();
	}
}