//2010.05.21 FJC
//隊首可開走
#include<stdio.h>
#include<malloc.h>
#define maxsize 2
typedef int datatype;      //佇列開始
typedef struct node
{
	datatype data;
	struct node *next;
}linklist;
typedef struct
{linklist *front,*rear;
}linkqueue;
linkqueue *creat(q)
linkqueue *q;
{q->front=(linklist*)malloc(sizeof(linklist));
 q->front->next=NULL;
 q->rear=q->front;
 return q;
}
int isnull(q)
linkqueue *q;
{if(q->front==q->rear)
    return 1;
 else
	 return 0;
}
linkqueue *enqueue(q,x)
linkqueue *q;                 
datatype x;
{
	q->rear->next=(linklist*)malloc(sizeof(linklist));
	q->rear=q->rear->next;
	q->rear->data=x;
	q->rear->next=NULL;
	return q;
}
datatype dequeue(q)
linkqueue *q;
{
	linklist *s;
	if(isnull(q))
	{printf("queue is empty!\n");
	 return NULL;
	}
	else
	{s=q->front;
	 q->front=q->front->next;
	 free(s);
	 return(q->front->data);
	}
} 
datatype headqueue(q)
linkqueue *q;
{
	linklist *s;
	if(isnull(q))
	{return NULL;
	}
	else
	{return(q->front->next->data);//注意頭結點
	}
} 
int dequeue2(q,x)
linkqueue *q;
datatype x;
{
	linklist*s;
	s=q->front;
	while(s->data!=x)
	{
	}
}
//佇列結束
typedef struct
{
	datatype data;
	datatype time;
}stackdata;
typedef struct
{
    stackdata data[maxsize];
    int top;
}stack;
stack* creatstack()
{stack *s;
 s=(stack*)malloc(sizeof(stack));
 s->top=-1;
 return s;
}
int isempty(stack *s)
{if(s->top==-1)
     return 1;
  else
	  return 0;
}
int isfull(stack *s)
{if(s->top==maxsize-1)
    return 1;
 else
	 return 0;
}
void push(stack *s,datatype x,datatype y)
{if(isfull(s))
     printf("overflow!\n");
 else
 {
	 s->top++;
     s->data[s->top].data=x;
	 s->data[s->top].time=y;
 }
}
void push2(stack *s,stackdata data)
{
	 s->top++;
     s->data[s->top]=data;
}
stackdata pop(stack *s)
{if(isempty(s));
 else
 {s->top--;
  return(s->data[s->top+1]);
 }
}
datatype top(stack *s)
{if(!isempty(s))
    {return (s->data[s->top].data);}
return NULL;
}
int execute(que,s1,s2,sign,x,y)
linklist *que;
stack *s1,*s2;
char sign;
datatype x;
datatype y;
{
	datatype t,t1;
	stackdata data;
	datatype dat;
	if(sign=='A')
	{if(!isfull(s1))
	{push(s1,x,y);
	 printf("%d車於%d時進入停車場\n",x,y);
	}
	 else
	 {enqueue(que,x);
	  printf("%d車於%d時在便道上停車\n",x,y);}
	}
	if(sign=='B')
	{
	  if(headqueue(que)==x)
	  {
			   dequeue(que);
			   printf("便道上的車%d於%d時開走\n",x,y);
			   return 1;
	  }
		if(isempty(s1))
		{printf("停車場內無車輛！\n");}
		else
		{
           while(x!=top(s1)&&s1->top!=-1)
		   {data=pop(s1);
	        push2(s2,data);
		   }
		  if(s1->top==-1)
		  {printf("無此車輛！\n");
		   return 0;
		  }
     	  t1=pop(s1).time;
	      t=y-t1;
		  if(t>=0)
		  {printf("%d車於%d時開出停車場，共用時%d\n",x,y,t);
    	   while(!isempty(s2))
		   {data=pop(s2);
	        push2(s1,data);
		   }
	       if(!isnull(que))
		   { dat=dequeue(que);
	         push(s1,dat,y);
	       	 printf("%d車於%d時進入停車場\n",dat,y);
		   }
		  }
		  else
		  {printf("輸入有誤！\n");
		   push(s1,x,t1);
		   return 0;
		  }
		}
	}
	return 1;
}
void main()
{
	char ch;
	datatype data,time;
	linkqueue *que=(linkqueue*)malloc(sizeof(linkqueue));
	stack *s1,*s2;
	que=creat(que);
	s1=creatstack();
	s2=creatstack();
	printf("                           ******停車場管理模擬系統******\n");
	printf("請輸入車輛資訊：\n");
	printf("汽車到達或離去資訊：\n");
	ch=getchar();
	while(ch!='E')
	{printf("輸入車號及到達時間（整數，空格分開）：\n");
	 scanf("%d%d",&data,&time);
	 execute(que,s1,s2,ch,data,time);
	 ch=getchar();//接收空格
	 printf("汽車到達或離去資訊：\n");
	 ch=getchar();
	}
	printf("程式結束\n");
}