Alternative stack.

alternative stack

In the sequential storage implementation of the stack, another method is to define Top as the previous position of the top of the stack. Please write a program to realize the push and pop operations of the defined lower stack. How to judge whether the stack is empty or full?

Function interface definition:

bool Push( Stack S, ElementType X );
ElementType Pop( Stack S );

where `Stack`the structure is defined as follows:

typedef int Position;
typedef struct SNode *PtrToSNode;
struct SNode {
    
    
    ElementType *Data;  /* 存储元素的数组 */
    Position Top;       /* 栈顶指针       */
    int MaxSize;        /* 堆栈最大容量   */
};
typedef PtrToSNode Stack;

Note: If the stack is full, Pushthe function must output "Stack Full" and return false; if the queue is empty, the Popfunction must output "Stack Empty" and return ERROR.

Sample referee test procedure:

#include <stdio.h>
#include <stdlib.h>

#define ERROR -1
typedef int ElementType;
typedef enum {
    
     push, pop, end } Operation;
typedef enum {
    
     false, true } bool;
typedef int Position;
typedef struct SNode *PtrToSNode;
struct SNode {
    
    
    ElementType *Data;  /* 存储元素的数组 */
    Position Top;       /* 栈顶指针       */
    int MaxSize;        /* 堆栈最大容量   */
};
typedef PtrToSNode Stack;

Stack CreateStack( int MaxSize )
{
    
    
    Stack S = (Stack)malloc(sizeof(struct SNode));
    S->Data = (ElementType *)malloc(MaxSize * sizeof(ElementType));
    S->Top = 0;
    S->MaxSize = MaxSize;
    return S;
}

bool Push( Stack S, ElementType X );
ElementType Pop( Stack S );

Operation GetOp();          /* 裁判实现，细节不表 */
void PrintStack( Stack S ); /* 裁判实现，细节不表 */

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

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

/* 你的代码将被嵌在这里 */

Input sample:

4
Pop
Push 5
Push 4
Push 3
Pop
Pop
Push 2
Push 1
Push 0
Push 10
End

Sample output:

Stack Empty
3 is out
4 is out
Stack Full
0 1 2 5

代码长度限制			16 KB
时间限制				400 ms
内存限制				64 MB

Answer:

bool Push( Stack S, ElementType X ){
    
    

if(S->Top==S->MaxSize)
{
    
    
	printf("Stack Full\n");
   return false;
   
}
else
{
    
    
	S->Data[S->Top]=X;
	S->Top++;
}
   return true;
}
ElementType Pop( Stack S )
{
    
    
	if(S->Top==0)
	{
    
    
		printf("Stack Empty\n");
		return ERROR;
	}
	else
	{
    
    
		S->Top--;
	}
	return S->Data[S->Top];
}

test:

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