6-1 在一個陣列中實現兩個堆疊 (20分)

本題要求在一個陣列中實現兩個堆疊。

函式介面定義：
Stack CreateStack( int MaxSize );
bool Push( Stack S, ElementType X, int Tag );
ElementType Pop( Stack S, int Tag );
其中Tag是堆疊編號，取1或2；MaxSize堆疊陣列的規模；Stack結構定義如下：

typedef int Position;
struct SNode {
ElementType *Data;
Position Top1, Top2;
int MaxSize;
};
typedef struct SNode *Stack;
注意：如果堆疊已滿，Push函式必須輸出“Stack Full”並且返回false；如果某堆疊是空的，則Pop函式必須輸出“Stack Tag Empty”（其中Tag是該堆疊的編號），並且返回ERROR。

裁判測試程式樣例：
#include <stdio.h>
#include <stdlib.h>

#define ERROR 1e8
typedef int ElementType;
typedef enum { push, pop, end } Operation;
typedef enum { false, true } bool;
typedef int Position;
struct SNode {
ElementType *Data;
Position Top1, Top2;
int MaxSize;
};
typedef struct SNode *Stack;

Stack CreateStack( int MaxSize );
bool Push( Stack S, ElementType X, int Tag );
ElementType Pop( Stack S, int Tag );

Operation GetOp(); /* details omitted /
void PrintStack( Stack S, int Tag ); / details omitted */

int main()
{
int N, Tag, X;
Stack S;
int done = 0;

scanf("%d", &N);
S = CreateStack(N);
while ( !done ) {
    switch( GetOp() ) {
    case push: 
        scanf("%d %d", &Tag, &X);
        if (!Push(S, X, Tag)) printf("Stack %d is Full!\n", Tag);
        break;
    case pop:
        scanf("%d", &Tag);
        X = Pop(S, Tag);
        if ( X==ERROR ) printf("Stack %d is Empty!\n", Tag);
        break;
    case end:
        PrintStack(S, 1);
        PrintStack(S, 2);
        done = 1;
        break;
    }
}
return 0;

}

/* 你的程式碼將被嵌在這裡 */
輸入樣例：
5
Push 1 1
Pop 2
Push 2 11
Push 1 2
Push 2 12
Pop 1
Push 2 13
Push 2 14
Push 1 3
Pop 2
End
輸出樣例：
Stack 2 Empty
Stack 2 is Empty!
Stack Full
Stack 1 is Full!
Pop from Stack 1: 1
Pop from Stack 2: 13 12 11

Stack CreateStack(int MaxSize)
{
	Stack S;
	S=(Stack)malloc(sizeof(struct SNode));
	S->Data=(int *)malloc(MaxSize*sizeof(int));
	S->Top1=-1;
	S->Top2=MaxSize;
	S->MaxSize=MaxSize;
	return S;
 } 
 bool Push( Stack S, ElementType X, int Tag )
 {
 	if(S->Top2-S->Top1==1)
 	{
 		printf("Stack Full\n");
 		return false;
	 }
	 if(Tag==1)
	 {
	 	S->Data[(S->Top1)++]=X;
	 }
	 else
	 S->Data[(S->Top2)--]=X;
	 
 }
 ElementType Pop( Stack S, int Tag )
 {
 	if(Tag==1)
 	{
 		if(S->Top1==-1)
 		{
 			printf("Stack %d Empty\n",Tag);
 			return ERROR;
		 }
		 else return S->Data[--(S->Top1)];
	 }
	 if(Tag==2)
 	{
 		if(S->Top2==S->MaxSize)
 		{
 			printf("Stack %d Empty\n",Tag);
 			return ERROR;
		 }
		 else return S->Data[++(S->Top2)];
	 }
 }