@https://pintia.cn/problem-sets/15/problems/730

6-7 在一個數組中實作兩個堆棧 (20 point(s))

本題要求在一個數組中實作兩個堆棧。

函數接口定義：

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

其中

Tag

是堆棧編号，取

1

或

2

；

MaxSize

堆棧數組的規模；

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：如果堆棧已滿，

Push

函數必須輸出“

Stack Full

”并且傳回

false

；如果某堆棧是空的，則

Pop

函數必須輸出“

Stack Tag Empty

”（其中

Tag

是該堆棧的編号），并且傳回

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;
}

/* 你的代碼将被嵌在這裡 */
           

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
           

代碼實作©

Stack CreateStack(int MaxSize)
{
    Stack p = (Stack)malloc(sizeof(struct SNode));
    p->Data = (int*)malloc(MaxSize * sizeof(int));
    p->Top1 =- 1;
    p->Top2 = MaxSize;
    p->MaxSize = MaxSize;
    return p;
}
bool Push(Stack S, ElementType X, int Tag)
{
    if (S->Top2 - S->Top1 == 1)
    {
        puts("Stack Full");
        return 0;
    }
    if (Tag == 1)
        S->Data[++(S->Top1)] = X;
    else S->Data[--(S->Top2)] = X;
    return 1;
}
ElementType Pop(Stack S, int Tag)
{
    if (Tag == 1)
    {
        if (S->Top1 == -1)
        {
            printf("Stack %d Empty\n", Tag);
            return ERROR;
        }
        return S->Data[(S->Top1)--];
    }
    else
    {
        if (S->Top2 == S->MaxSize)
        {
            printf("Stack %d Empty\n", Tag);
            return ERROR;
        }
        return S->Data[(S->Top2)++];
    }
}