stack.c

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/* Copyright (c) 2005 by John M. Boyer, All Rights Reserved.  Please see
 * License.txt for use and redistribution license. */
/* Copyright (c) 1997 by John M. Boyer, All Rights Reserved.
        This code may not be reproduced or disseminated in whole or in part 
        without the written permission of the author. */

#include "appconst.h"
#include "stack.h"
#include <stdlib.h>
stackP sp_New (int Size)
{
  stackP theStack;
  theStack = (stackP) malloc (sizeof (stack));
  if (theStack != NULL)

  {
    theStack->S = (int *) malloc (Size * sizeof (int));
    if (theStack->S == NULL)

    {
      free (theStack);
      theStack = NULL;
    }
  }
  if (theStack != NULL)

  {
    theStack->Size = Size;
    sp_ClearStack (theStack);
  }
  return theStack;
}

void sp_Free (stackP * pStack)
{
  if (pStack == NULL || *pStack == NULL)
    return;
  (*pStack)->Size = (*pStack)->Top = 0;
  if ((*pStack)->S != NULL)
    free ((*pStack)->S);
  (*pStack)->S = NULL;
  free (*pStack);
  *pStack = NULL;
}

int sp_Copy (stackP stackDst,
             stackP stackSrc)
{
  stackP newStack = NULL;
  int I,
   *p;
  if (stackDst->Size == stackSrc->Size)

  {
    for (I = 0; I < stackSrc->Top; I++)
      stackDst->S[I] = stackSrc->S[I];
  }

  else

  {
    newStack = sp_New (stackSrc->Size);
    if (newStack == NULL)
      return NOTOK;
    for (I = 0; I < stackSrc->Top; I++)
      newStack->S[I] = stackSrc->S[I];
    p = stackDst->S;
    stackDst->S = newStack->S;
    newStack->S = p;
    newStack->Size = stackDst->Size;
    sp_Free (&newStack);
  }
  stackDst->Top = stackSrc->Top;
  stackDst->Size = stackSrc->Size;
  return OK;
}


#ifndef SPEED_MACROS
int sp_ClearStack (stackP theStack)
{
  theStack->Top = 0;
  return OK;
}

int sp_IsEmpty (stackP theStack)
{
  return !theStack->Top;
}

int sp_NonEmpty (stackP theStack)
{
  return theStack->Top;
}

int sp_Push (stackP theStack,
             int a)
{

//     if (theStack->Top >= theStack->Size)
//         return NOTOK;
  theStack->S[theStack->Top++] = a;
  return OK;
}

int sp_Push2 (stackP theStack,
              int a,
              int b)
{

//     if (theStack->Top + 1 >= theStack->Size)
//         return NOTOK;
  theStack->S[theStack->Top++] = a;
  theStack->S[theStack->Top++] = b;
  return OK;
}

int sp__Pop (stackP theStack,
             int *pA)
{

//     if (theStack->Top <= 0)
//         return NOTOK;
  *pA = theStack->S[--theStack->Top];
  return OK;
}

int sp__Pop2 (stackP theStack,
              int *pA,
              int *pB)
{

//     if (theStack->Top <= 1)
//         return NOTOK;
  *pB = theStack->S[--theStack->Top];
  *pA = theStack->S[--theStack->Top];
  return OK;
}


#endif // SPEED_MACROS

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