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linklist.c

/* LinkList.C -- ANSI C Linked List Container Type
                 Handles Lists, Queues, Stacks, Splay trees,
               and custom list types via one consistant interface. 

               - Written by Jeff Hay, jrhay@lanl.gov 
*/

#include "linklist.h"
#include <string.h>

listPtr NewListAlloc(int ListType, ListAlloc Lalloc, ListFreeFunc Lfree, 
                 NodeCompareFunc Cfunc)
{
  listPtr List;

  if (Lalloc == NULL) Lalloc = malloc;
  if (Lfree == NULL)  Lfree = free;

  if ((List = (listPtr)((Lalloc)(sizeof(struct LList)))) != NULL)
    {
      List->Current  = List->Head = List->Tail = NULL;
      List->memalloc = Lalloc;
      List->memfree  = Lfree;
      List->compare  = Cfunc;
      List->Size     = 0;
      List->Flags    = ListType;
    }

  return List;
} /* NewListAlloc() */

listnodePtr NewListNode(listPtr List, void *Data)
{
  listnodePtr Node;
  ListAlloc  Alloc;

  if (List == NULL)
    Alloc = malloc;
  else
    Alloc = List->memalloc;
    
  if ((Node = (listnodePtr)((Alloc(sizeof(struct ListNode))))) != NULL)
    {
       Node->Data = Data;
       Node->Next = Node->Prev = NULL;
    }

  return Node;
} /* NewListNode() */

void *GetNode(listPtr List)
{
  void *Data;
  int  Delete;

  if (List == NULL) return NULL;

  Data   = NULL;
  Delete = ((List->Flags & LISTFLAGMASK) & LISTDELREAD);

  switch (List->Flags & LISTREADMASK) 
    {
       case LISTREADHEAD: if (List->Head != NULL) {
                          Data = List->Head->Data;
                      if (Delete) DelHeadList(List);
                          }
                          break;
       case LISTREADTAIL: if (List->Tail != NULL) {
                            Data = List->Tail->Data;
                            if (Delete) DelTailList(List);
                          }
                          break;
       default:  
       case LISTREADCURR: if (List->Current != NULL) {
                            Data = List->Current->Data;
                          if (Delete) RemoveList(List);
                          }
                          break;
    }

  return Data;
} /* GetNode() */

void *GetNodeData(listnodePtr Node)
{
  if (Node != NULL)
    return Node->Data;
   else
    return NULL;
} /* GetNodeData() */

void *FindNode(listPtr List, void *Data)
{
  int Compare;

  if ((List == NULL) || (List->compare == NULL))
    return NULL;

  if ((List->Flags & LISTADDMASK) & LISTADDSPLAY)
    { /* List is a splay tree; do weirdness... */
      if (SplayList(List, Data) != NULL)
              Compare = 0;
    }
  if ((List->Flags & LISTFLAGMASK) & LISTBTREE)
    { /* List is some other binary tree, do a binary tree search... */
      if (BTFind(List, Data) != NULL)
              Compare = 0;
    }
  else
    { /* List is a normal list, not a tree, step through it... */
      
      List->Current = List->Head;
      if (List->Current == NULL)
              return NULL;
      
      while ((Compare = (List->compare)(List->Current->Data, Data)) != 0) {
              List->Current = List->Current->Next;
              if (List->Current == NULL)
                    return NULL; // end of list
        }
    }

  if (Compare != 0)
    return NULL;
  else
    return List->Current->Data;

} /* FindNode() */

void *BTFind(listPtr List, void *Data)
{
  int Compare;

  if ((List == NULL) || (List->compare == NULL))
    return NULL;

  Compare = 1;
  while ((Compare != 0) && (List->Current != NULL))
    {
      if ((Compare = (List->compare)(List->Current->Data, Data) != 0))
      {
        if (Compare < 0)
          List->Current = List->Current->Next;
        else 
          List->Current = List->Current->Prev;
      }
    }

  if (List->Current != NULL)
    return List->Current->Data;
  else
    return NULL;
} /* BTFind() */


int AddNode(listPtr List, listnodePtr Node)
{
  if (List == NULL) return LLIST_NULL;

  switch (List->Flags & LISTADDMASK) 
    {
       case LISTADDCURR: return InsertList(List, Node); break;
       case LISTADDHEAD: return HeadList(List, Node); break;
       case LISTADDTAIL: return TailList(List, Node); break;
       case LISTADDSPLAY: return SplayInsertList(List, Node); break;
     default: return InsertList(List, Node); break; 
    }

  return LLIST_ERROR;
} /* AddNode() */

int SplayInsertList(listPtr List, listnodePtr Node)
{
  if (List == NULL) return LLIST_NULL;
  if (Node == NULL) return LLIST_NULL;

  if (List->Head != NULL) /* empty tree? */
    {
      if (SplayList(List, Node->Data) != NULL)
      /* We found this element in the splay tree; this is bad.  Say so... */
      return LLIST_BADVALUE;

      if ((List->compare)(Node->Data, List->Head->Data) > 0)
      {
        Node->Prev = List->Head;
        if ((List->compare)(Node->Data, GetNodeData(List->Head->Next)) < 0)
          {
            Node->Next = List->Head->Next;
            List->Head->Next = NULL;
          }
      }
      else
      {
        Node->Next = List->Head;
        if ((List->compare)(Node->Data, GetNodeData(List->Head->Prev)) > 0)
          {
            Node->Prev = List->Head->Prev;
            List->Head->Prev = NULL;
          }
      }
    }

  List->Head = List->Current = Node;
  List->Size++;

  return LLIST_NOERROR;
} /* SplayInsertList() */

int InsertList(listPtr List, listnodePtr Node)
{
  if (List == NULL) return LLIST_NULL;
  if (Node == NULL) return LLIST_NULL;

  if (List->Current != NULL)
    {
      Node->Prev = List->Current;
      Node->Next = List->Current->Next;
      List->Current->Next = Node;

      if (Node->Next == NULL)
        List->Tail = Node;
      else
      Node->Next->Prev = Node;
    }
  List->Current = Node;

  if (++List->Size == 1) /* If List Was Empty... */
    {
      List->Head = Node;
      List->Tail = Node;
    }

  return LLIST_NOERROR;
} /* InsertList() */

int HeadList(listPtr List, listnodePtr Node)
{
  if (List == NULL) return LLIST_NULL;
  if (Node == NULL) return LLIST_NULL;

  if (List->Head != NULL)
    {
      Node->Next = List->Head;
      List->Head->Prev = Node;
    }

  List->Head = Node;
  List->Current = Node;

  if (++List->Size == 1) /* If List Was Empty... */
    List->Tail = Node;

  return LLIST_NOERROR;
} /* HeadList() */

int TailList(listPtr List, listnodePtr Node)
{
  if (List == NULL) return LLIST_NULL;
  if (Node == NULL) return LLIST_NULL;

  if (List->Tail != NULL)
    {
      Node->Prev = List->Tail;
      List->Tail->Next = Node;
    }
     
  List->Tail = Node;
  List->Current = Node;

  if (++List->Size == 1) /* If List Was Empty... */
    List->Head = Node;

  return LLIST_NOERROR;
} /* TailList() */
  
int SplayRemoveList(listPtr List)
{
  listnodePtr _DelNode;

  if (List == NULL) return LLIST_NULL;
  if (List->Head == NULL) return LLIST_NOERROR;

  /* Assumes List->Head (root of splay tree) is already selected to
     be deleted node */

  _DelNode = List->Head;
  if (List->Head->Next == NULL)
    List->Head = List->Head->Prev;
  else 
    {
      if (List->Head->Prev != NULL)
      {
        SplayList(List, List->Head->Prev->Data);   /* Must succeed */
        List->Head->Next = _DelNode->Next;
      }
      else
      List->Head = List->Head->Next;
    }
  
  List->memfree(_DelNode);
  List->Current = List->Head;
  
  List->Size--;
  return LLIST_NOERROR;
} /* SplayRemoveList() */

int DelNode(listPtr List)
{
  if (List == NULL) return LLIST_NULL;

  switch (List->Flags & LISTDELMASK) 
    {
       case LISTDELCURR: return RemoveList(List); break;
       case LISTDELHEAD: return DelHeadList(List); break;
       case LISTDELTAIL: return DelTailList(List); break;
       case LISTDELSPLAY: return SplayRemoveList(List); break;
      default: return RemoveList(List); break; 
    }

  return LLIST_ERROR;
} /* DelNode() */

int RemoveList(listPtr List)
{
  listnodePtr Temp;

  if (List == NULL) return LLIST_NULL;

  if (List->Current == NULL)
    return LLIST_NOERROR;

  if (List->Current == List->Head)
    return DelHeadList(List);

  if (List->Current == List->Tail)
    return DelTailList(List);

  Temp = List->Current;

  Temp->Prev->Next = List->Current->Next;
  Temp->Next->Prev = List->Current->Prev;

  List->Current = List->Current->Next;

  List->memfree(Temp);
  
  List->Size--;

  return LLIST_NOERROR;
} /* RemoveList() */

int DelHeadList(listPtr List)
{
  listnodePtr Temp;

  if (List == NULL) return LLIST_NULL;

  if (List->Head == NULL)
    return LLIST_NOERROR;

  Temp = List->Head;

  if (Temp->Next != NULL)
    Temp->Next->Prev = NULL;
  List->Head = Temp->Next;
  List->Current = List->Head;

  List->memfree(Temp);

  List->Size--;

  return LLIST_NOERROR;
} /* DelHeadList() */

int DelTailList(listPtr List)
{
  listnodePtr Temp;

  if (List == NULL) return LLIST_NULL;

  if (List->Tail == NULL)
    return LLIST_NOERROR;

  Temp = List->Tail;

  if (Temp->Prev != NULL)
    Temp->Prev->Next = NULL;
  List->Tail = Temp->Prev;
  List->Current = List->Tail;
  
  List->memfree(Temp);

  List->Size--;

  return LLIST_NOERROR;
} /* DelTailList() */

void *NextNode(listPtr List)
{
  if (List == NULL) 
    return NULL;

  if (List->Current != NULL)
    List->Current = List->Current->Next;

  if ((List->Flags & LISTFLAGMASK) & LISTCIRCULAR)
    if (List->Current == NULL)
      List->Current = List->Head;

  return GetNodeData(List->Current);
} /* NextNode() */

void *PrevNode(listPtr List)
{
  if (List == NULL) 
    return NULL;

  if (List->Current != NULL)
    List->Current = List->Current->Prev;

  if ((List->Flags & LISTFLAGMASK) & LISTCIRCULAR)
    if (List->Current == NULL)
      List->Current = List->Tail;

  return GetNodeData(List->Current);
} /* PrevNode() */

void *IndexNode(listPtr List, int Index)
{
  int Count;

  if ((List == NULL) ||
      ((List->Flags & LISTFLAGMASK) & LISTBTREE))      
    return NULL;

  if (List->Size < Index)
    return NULL;

  List->Current = List->Head;
  for (Count = 1; Count < Index; Count++)
    List->Current = List->Current->Next;

  return GetNodeData(List->Current);
} /* IndexNode() */

int FreeList(listPtr List, ListFreeFunc DataFree)
{
  int Delete;

  if (List == NULL) return LLIST_NULL;

  List->Current = List->Head;
  Delete = LLIST_NOERROR;
  while ((Delete == LLIST_NOERROR) && (List->Size > 0))
    {
      if ((DataFree != NULL)  && (List->Head->Data != NULL))
      DataFree(List->Head->Data);
      
      if ((List->Flags & LISTDELMASK) & LISTDELSPLAY)
      Delete = SplayRemoveList(List);
      else
      Delete = DelHeadList(List);
    }  

  if (Delete == LLIST_NOERROR)
    List->memfree(List);

  return Delete;
} /* FreeList() */ 

void SwapList(listPtr List)
{
  listnodePtr Temp1, Temp2;

  if ((List == NULL) || (List->Current == NULL) || 
      (List->Current->Next == NULL))
    return;             

  Temp1 = List->Current;
  Temp2 = List->Current->Next;
  
  Temp1->Next = Temp2->Next;
  if (Temp2->Next != NULL)
    Temp2->Next->Prev = Temp1;
  else
    List->Tail = Temp1;

  Temp2->Prev = Temp1->Prev;
  if (Temp1->Prev != NULL)
    Temp1->Prev->Next = Temp2;
  else
    List->Head = Temp2;

  Temp1->Prev = Temp2;
  Temp2->Next = Temp1;

  return;
} /* SwapList() */

void SortList(listPtr List)
{
  int Move;

  if ((List == NULL) || (List->compare == NULL) ||
      ((List->Flags & LISTFLAGMASK) & LISTBTREE))
    return;

  /* This is a DA-sort!! */

  if (List->Head == NULL)
    return;

  Move = 1;
  while (Move != 0)
    {
      Move = 0;
      List->Current = List->Head;
      while (List->Current->Next != NULL)
      {
        if ((List->compare)(List->Current->Data, 
                        List->Current->Next->Data) > 0)
          {
            Move++;
            SwapList(List);
          };

        if (List->Current->Next != NULL)
          List->Current = List->Current->Next;
      }
    }

  List->Current = List->Head;
  return;
} /* SortList() */


void *SplayList(listPtr List, void *Data)
{
  listnodePtr Temp, Left, Right, LeftRoot, RightRoot;
  int Test;

  if ((List == NULL) || (List->compare == NULL))
    return NULL;

  /* Implements a top-down splay on the list; that is, it splays as it
     searches down the list for Data. (Basic algorithm from Sleator and
     Tarjan's "Self-Adjusting Binary Search Trees" paper of 1985) */

  List->Current = List->Head;
  if (List->Current == NULL)
    return NULL;
  Left = LeftRoot = Right = RightRoot = NULL;
  for (;;) {
    if ((Test = (List->compare)(Data, List->Current->Data)) < 0)
      {
      if (List->Current->Prev == NULL)
        break;
      if ((List->compare)(Data, List->Current->Prev->Data) < 0)
        {
          Temp = List->Current->Prev;
          List->Current->Prev = Temp->Next;
          Temp->Next = List->Current;
          List->Current = Temp;
          if (List->Current->Prev == NULL)
            break;
        }
      if (Right == NULL)
        Right = RightRoot = List->Current;
      else
        {
          Right->Prev = List->Current;
          Right = List->Current;
        }
      List->Current = List->Current->Prev;
      }
    else if (Test > 0)
      {
      if (List->Current->Next == NULL)
        break;
      if ((List->compare)(Data, List->Current->Next->Data) > 0)
        {
          Temp = List->Current->Next;
          List->Current->Next = Temp->Prev;
          Temp->Prev = List->Current;
          List->Current = Temp;
          if (List->Current->Next == NULL)
            break;
        }
      if (Left == NULL)
        Left = LeftRoot = List->Current;
      else
        {
          Left->Next = List->Current;
          Left = List->Current;
        }
      List->Current = List->Current->Next;
      }
    else
      break;
  }

  if (List->Current == NULL)
    return NULL;

  if (Left != NULL)
    Left->Next = List->Current->Prev;
  else
    LeftRoot = List->Current->Prev;

  if (Right != NULL)
    Right->Prev = List->Current->Next;
  else
    RightRoot = List->Current->Next;

  /* This assignment order is backwards from example code, but seems
     to work... (and makes more intuitive sense) */
  List->Current->Next = RightRoot;
  List->Current->Prev = LeftRoot;

  List->Head = List->Current;
  if ((List->compare)(Data, List->Head->Data) == 0)
    return List->Head;
  else
    return NULL;
} /* SplayList() */

int StringCompare(char *First, char* Second)
{
  /* printf("comparing \"%s\" to \"%s\"\n", First, Second); */
  if ((First != NULL) && (Second != NULL))
    return strcmp(First, Second);
  else
    return 0;
} /* StringCompare() */
  
int IntCompare(int *First, int* Second)
{
  if ((First == NULL) || (Second == NULL))
    return 0;

  if (*First > *Second)
    return 1;

  if (*First < *Second)
    return -1;

  return 0;
} /* IntCompare() */
  
int DoubleCompare(double *First, double* Second)
{
  if ((First == NULL) || (Second == NULL))
    return 0;

  if (*First > *Second)
    return 1;

  if (*First < *Second)
    return -1;

  return 0;
} /* DoubleCompare() */
  
/*
    End of LinkList Library - Remainder of code is for
       the demonstration/test routines
       
*/

int DumpList(listPtr List, ListDumpFunc DataDump) 
/* Print List data using the DataDump function for Node Data Elements */
{
  int Count;
  listnodePtr Position;

  if (List == NULL) return LLIST_BADVALUE;

  Position = List->Current;
  List->Current = List->Head;
  
  for (Count = 1; Count <= List->Size; Count++)
    {
      DataDump(GetNodeData(List->Current));    
      NextNode(List);
    }

  List->Current = Position;

  return LLIST_NOERROR;
}

#ifdef LINKLIST_TEST

#include <string.h>  /* for strcmp() comparison procedure */

int PrintList(listPtr List, char *DataFmt)
  /* Print List using DataFmt as the printf() format for Node Data Elements */
{
  int Count;
  listnodePtr Position;
  char OutStr[30];

  if (List == NULL) return LLIST_BADVALUE;
  if (List->Flags & LISTBTREE) return PrintTree(List, DataFmt);

  strcpy(OutStr, "\tHead: ");
  strcat(OutStr, DataFmt);
  strcat(OutStr, "\tTail: ");
  strcat(OutStr, DataFmt);
  strcat(OutStr, "\n");
  printf(OutStr, GetNodeData(List->Head), GetNodeData(List->Tail));

  strcpy(OutStr, "Index: %d\tData: ");
  strcat(OutStr, DataFmt);
  strcat(OutStr, "\n");

  Position = List->Current;
  List->Current = List->Head;
  for (Count = 1; Count <= List->Size; Count++)
    {
      printf(OutStr, Count, GetNodeData(List->Current));
      NextNode(List);
    }
  List->Current = Position;

  return LLIST_NOERROR;
} /* PrintList */

void GraphicTree(listnodePtr Node, char *DataFmt, int Level)
/* Recursive procedure to print the structure of a binary tree.  From
   example code by Matthew Weathers at Biola University */
{
  int Count;
  char OutStr[30];  

  if (Node != NULL)
    {
      for (Count = 0; Count < Level; Count++)
      printf("\t");
      strcpy(OutStr, "\"");
      strcat(OutStr, DataFmt);
      strcat(OutStr, "\" (left=\"");
      strcat(OutStr, DataFmt);
      strcat(OutStr, "\", right=\"");
      strcat(OutStr, DataFmt);
      strcat(OutStr, "\")\n");
      
      printf(OutStr, GetNodeData(Node),
           GetNodeData(Node->Prev), GetNodeData(Node->Next));
      GraphicTree(Node->Prev, DataFmt, Level + 1);
      GraphicTree(Node->Next, DataFmt, Level + 1);
    }
}

int PrintTree(listPtr List, char *DataFmt)
{
  listnodePtr Parent;

  if (List == NULL) return LLIST_BADVALUE;

  printf("\nTree: (%d Nodes)\n", List->Size);
  GraphicTree(List->Head, DataFmt, 0);
  printf("\n");

  return LLIST_NOERROR;
} /* PrintTree */

/* ---
   End of simple debugging malloc wrappers
--- */

int main()
{
  listPtr List, Queue, Stack, Splay;
  char *String1, *String2, *String3, *String4, *Get;
  int Result;

  printf("Testing LINKLIST Library for ANSI C.\n\n");

  String1 = malloc(20);
  String2 = malloc(20);
  String3 = malloc(20);
  String4 = malloc(20);
  strcpy(String1, "Hi");
  strcpy(String2, "Low");
  strcpy(String3, "Up");
  strcpy(String4, "Down");

  printf("Creating List.\n");
  List = NewListAlloc(LIST, DMALLOC, DFREE, (NodeCompareFunc)strcmp);
  printf("Creating Queue.\n");
  Queue = NewListAlloc(QUEUE, DMALLOC, DFREE, NULL);
  printf("Creating Stack.\n");
  Stack = NewListAlloc(STACK, DMALLOC, DFREE, NULL);
  printf("Creating Splay Tree\n");
  Splay = NewListAlloc(STREE, DMALLOC, DFREE, (NodeCompareFunc)StringCompare);

  printf("Adding Elements to List...\n");
  AddNode(List, NewNode("Hi"));
  AddNode(List, NewNode("Low"));
  AddNode(List, NewNode("Up"));
  AddNode(List, NewNode("Down"));

  printf("Adding Elements to Queue...\n");
  AddNode(Queue, NewNode("Hi"));
  AddNode(Queue, NewNode("Low"));
  AddNode(Queue, NewNode("Up"));
  AddNode(Queue, NewNode("Down"));

  printf("Adding Elements to Stack...\n");
  AddNode(Stack, NewNode(String1));
  AddNode(Stack, NewNode(String2));
  AddNode(Stack, NewNode(String3));
  AddNode(Stack, NewNode(String4));

  printf("Adding Elements to Splay Tree...\n");
  AddNode(Splay, NewNode("High"));
  AddNode(Splay, NewNode("Low"));
  AddNode(Splay, NewNode("Up"));
  AddNode(Splay, NewNode("Down"));

  printf("Attempting to add duplicate nodes to Splay Tree...\n");
  Result = AddNode(Splay, NewNode("Down"));
  printf("Result: ");
  if (Result == LLIST_OK)
    printf("OK\n");
  else if (Result == LLIST_BADVALUE)
    printf("Node Already Exists; not added\n");
  else printf("Error\n");

  printf("Calimed Memory: %d bytes\n", DCOUNT(NULL));

  printf("LIST:\n");
  PrintList(List, "%s");
  printf("QUEUE:\n");
  PrintList(Queue, "%s");
  printf("STACK:\n");
  PrintList(Stack, "%s");
  printf("SPLAY:\n");
  PrintList(Splay, "%s");
  
  printf("\n-----------------------\n");

  printf("Reading Element from LIST\n");
  printf("Read Element: %s\n", GetNode(List));
  PrintList(List, "%s");

  printf("\n\nReading Element from QUEUE\n");
  printf("Read Element: %s\n", GetNode(Queue));
  PrintList(Queue, "%s");

  printf("\n\nReading Element from STACK\n");
  printf("Read Element: %s\n", (Get = GetNode(Stack)));
  DFREE(Get);
  PrintList(Stack, "%s");

  printf("\n-----------------------\n");

  printf("Reading Element #2 from LIST\n");
  printf("Read Element: %s\n", IndexNode(List, 2));
  PrintList(List, "%s");

  printf("\nAdding One More Element to LIST\n");
  AddNode(List, NewNode("And"));
  PrintList(List, "%s");

  printf("\n-----------------------\n");

  printf("\nSorting LIST\n");
  SortList(List);
  PrintList(List, "%s");

  printf("\n-----------------------\n");
  
  printf("\nDeleting Element 2 From LIST\n");
  IndexNode(List, 2);
  RemoveList(List);
  PrintList(List, "%s");

  printf("\nDeleting Head From LIST\n");
  DelHeadList(List);
  PrintList(List, "%s");

  printf("\nDeleting Tail From LIST\n");
  DelTailList(List);
  PrintList(List, "%s");

  printf("\n------------------------\n");
  
  printf("Reading Element from Splay Tree\n");
  printf("Read Element: %s\n", GetNode(Splay));

  printf("\nDeleting Element From Splay Tree\n");
  DelNode(Splay);
  PrintList(Splay, "%s");

  printf("\nDeleting Element \"Low\" In Splay Tree\n");
  FindNode(Splay, "Low");
  DelNode(Splay);
  PrintList(Splay, "%s");

  printf("Reading Element from Splay Tree\n");
  printf("Read Element: %s\n", GetNode(Splay));

  printf("\n-----------------------\n");

  printf("Removing List.\n");
  FreeList(List, NULL);
  printf("Removing Queue.\n");
  FreeList(Queue, NULL);
  printf("Removing Stack.\n");
  FreeList(Stack, NULL);
  printf("Removing Splay Tree.\n");
  FreeList(Splay, NULL);

  printf("\n-----------------------\n");
  
  printf("\nUnclaimed Memory: %d bytes\n", DCOUNT(NULL));

  printf("\nLinkList Test/Demo Done.\n");

  return 0;
} /* main */

#endif /* LINKLIST_TEST */












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