栈 ADT (数组实现)
头文件

#ifndef _Stack_Array_H

struct StackRecord;
typedef struct StackRecord *Stack;

int IsEmpty( Stack S );
int IsFull( Stack S );
Stack CreateStack( int MaxElements );
void DisposeStack( Stack S );
void MakeEmpty( Stack S );
void Push( ElementType X, Stack S );
ElementType Top( Stack S )
void Pop( Stack S );
ElementType TopAndPop( Stack S );

#endif /*_Stack_Array_H*/

/* Place in implementation file */
/* Stack implementation is a dynamically allocated array */
#define EmptyTOS ( -1 )
#define MinStackSize ( 5 )

struct StackRecord
{
	int Capacity;
	int TopOfStack;
	ElementType *Array;
};

详细例程

Stack CreateStack( int MaxElements )
{
	StackRecord S;

	if( MaxElements < MinStackSize )
		Error( "Stack size is too small!" );
	
	S = malloc( sizeof ( struct StackRecord ) );
	if( S == NULL )
		FatalError( "Out of space !!!" );
	
	S->Array = malloc( sizeof ( ElementType ) * MaxElements );
	if( S->Array == NULL )
		FatalError( "Out of space!!!" );
	S->Capacity = MaxElements;
	MakeEmpty( S );
	return S;
}

void MakeEmpty( Stack S )
{
	S->TopOfStack = EmptyTOS;
}

void DisposeStack( Stack S )
{
	if( S != NULL )
	{
		free( S-> Array );
		free( S );
	}
}

int IsEmpty( Stack S )
{
	return S->TopOfStack == EmptyTOS;
}

void Push( ElementType X, Stack S )
{
	if( IsFull( S ) )
		Error( "Full stack!" );
	else
		S->Array[ ++S->TopOfStack ] = X;
}

ElementType Top( Stack S )
{
	if( !IsEmpty( S ) )
		return S->Array[ S->TopOfStack-- ];
	Error( "Empty stack!" );
	return 0;
}

void Pop( Stack S )
{
	if( IsEmpty( S ) )
		Error( "Empty stack!" );
	else
		S->TopOfStack--;
}

ElementType TopAndPop( Stack S )
{
	if( !IsEmpty( S ) )
		return S->Array[ S->TopOfStack-- ];	
	Error( "Empty Stack" );
	return 0;
}