/*******************************************************************************
+
+  LEDA 7.2.3  
+
+
+  _eb_tree.c
+
+
+  Copyright (c) 1995-2026
+  by Algorithmic Solutions Software GmbH
+  All rights reserved.
+ 
*******************************************************************************/



#include <LEDA/core/impl/eb_tree.h>

// ----------------------------------------------------------
// Stefan  Naeher ( 1989 )
// Michael Wenzel ( 1990 ) 
// ----------------------------------------------------------
//
// Konstruktor & Destruktor
//

LEDA_BEGIN_NAMESPACE

l_stratified::l_stratified(stratified_ptr b, int x)
{
  int t = b->min2();

  if ( x == b->min() )
  { ma = t;
    mi = b->max();
   }

  if ( x == t )
  { ma = b->min();
    mi = b->max();
   }

  if ( x == b->max() )
  { ma = b->min();
    mi = t;
   }

}

stratified::stratified(int i)  
{ mi = ma = -1;
  sz = 0; 
  k = i;
  top = 0;
  bot = 0;
}

stratified::stratified(l_stratified_ptr l, int i)
{ mi = l->min();
  ma = l->max();
  sz = 2;
  k = i;
  top = 0;
  bot = 0;
}

stratified::~stratified()  
{ // deallocate memory of sub-structures
  if (k > 1 && sz > 2)
  {  // delete stratified trees of bot
    delete bot;

    if ( top->size() <= 2 )
      delete top;
    else
      delete (stratified_ptr)top;
  }
}

// ----------------------------------------------------------
//
// min2                  
//
// liefert 2. kleinstes Element, falls sz > 2
//
// -1 , sonst
//
// ----------------------------------------------------------

int stratified::min2()
{ if (sz < 3) return -1;
  int z = top->min();
  l_stratified_ptr l_bot_ptr = (l_stratified_ptr)bot->access(z);
  return mal_pot_2(z,down(k)) | l_bot_ptr->min();
}


// ----------------------------------------------------------
//
// max2                  
//
// liefert 2. groesstes Element, falls sz > 2
//
// -1 , sonst
//
// ----------------------------------------------------------

int stratified::max2()
{ if ( sz < 3 ) return -1;
  int z = top->max();
  l_stratified_ptr l_bot_ptr = (l_stratified_ptr)bot->access(z);
  return mal_pot_2(z,down(k)) | l_bot_ptr->max();
}


// ----------------------------------------------------------
//
// succ                  
//
// liefert Nachfolger von x im Baum auf dieser Rekursionsstufe
//                    falls existiert
// -1 , sonst
//
// ----------------------------------------------------------

int stratified::succ(int x) 
{
  if ( x >= ma ) return -1;
  if ( x <  mi ) return mi;
  if ( sz == 2 ) return ma;               // mi < x < ma

  // sz >= 2 &&  k>1
  int x1 = high_bits(x); 
  int x2 = low_bits(x); 

  b_dict_item it = bot->lookup(x1);
  GenPtr p = (it) ? bot->inf(it) : 0;

  l_stratified_ptr l_bot_ptr = (l_stratified_ptr)p;

  if ( (l_bot_ptr) && (l_bot_ptr->max()>x2) )
  { 
    if ( l_bot_ptr->size() <= 2 )             // l_stratified Struktur
        return ( mal_pot_2(x1,down(k))) | ( l_bot_ptr->succ(x2) ) ;
    else
    {
      stratified_ptr bot_ptr = (stratified_ptr)p;
      return (mal_pot_2(x1,down(k))) | (bot_ptr->succ(x2)) ;
    }
  }
  else                                   // succ nicht in bot-Unterstruktur
  {
    int z;
    
    if ( top->size() <= 2 )
      z = top->succ(x1); 
    else
      z = ((stratified_ptr)top)->succ(x1); 

    if ( z == -1 ) return ma;   // x unmittelbar vor Maximum

    l_stratified_ptr l_bot_ptr = (l_stratified_ptr)bot->access(z);

    return (mal_pot_2(z,down(k))) | (l_bot_ptr->min()) ;
  }

}

// ----------------------------------------------------------
//
// pred                  
//
// liefert Vorgaenger von x im Baum auf dieser Rekursionsstufe
//                    falls existiert
// -1 , sonst
//
// ----------------------------------------------------------

int stratified::pred(int x) 

{
  if ( x >  ma ) return ma;
  if ( x <= mi ) return -1;
  if ( sz == 2 ) return mi;               // mi < x < ma

                                          // sz > 2 && k > 1
  int x1 = high_bits(x); 
  int x2 = low_bits(x); 

  b_dict_item it = bot->lookup(x1);
  GenPtr p = (it) ? bot->inf(it) : 0;

  l_stratified_ptr l_bot_ptr = (l_stratified_ptr)p;

  if ( (l_bot_ptr) && (l_bot_ptr->min()<x2) ) 
  {
    if ( l_bot_ptr->size() <= 2 )             // l_stratified Struktur
        return ( mal_pot_2(x1,down(k))) | ( l_bot_ptr->pred(x2) ) ;
    else
    {
      stratified_ptr bot_ptr = stratified_ptr(p) ;
      return (mal_pot_2(x1,down(k))) | (bot_ptr->pred(x2)) ;
    }
  }
  else                                        // pred nicht in top-Unterstruktur
  {
    int z;

    if ( top->size() <= 2 )
      z = top->pred(x1); 
    else
      z = ((stratified_ptr)top)->pred(x1); 

    if ( z == -1 ) 
      return mi;                              // x unmittelbar vor Maximum

    l_stratified_ptr l_bot_ptr = (l_stratified_ptr)bot->access(z);

    return (mal_pot_2(z,down(k))) | (l_bot_ptr->max() ) ;
  }

} 

// --------------------------------------------------------------- 
//
// member   
//
// liefert 1, falls Element in der Struktur
//
//         0, sonst
//
// ----------------------------------------------------------

int stratified::member(int x)
{ 
  if (x == ma || x == mi) return 1;
  if (x <  mi || x >  ma) return 0;

  if (sz == 2) return 0;

  // sz > 2 && k > 1
  int x1 = high_bits(x); 
  int x2 = low_bits(x); 

  b_dict_item it = bot->lookup(x1);
  GenPtr p = (it) ? bot->inf(it) : 0;

  l_stratified_ptr l_bot_ptr = (l_stratified_ptr)p;

  if (l_bot_ptr)
  {
    if ( l_bot_ptr->size() <= 2 )    // l_stratified Struktur
      return l_bot_ptr->member(x2);

    else
    { stratified_ptr bot_ptr = stratified_ptr(p);
      return bot_ptr->member(x2);                  
     }
   }
  else
    return 0;                

}

// ----------------------------------------------------------
//
// insert           
//
// fuegt ein Element x rekursiv in den Baum ein
//
// liefert 1, falls es eingefuegt wurde
//
//         0, falls es schon Element dewr Struktur war
//
// ----------------------------------------------------------

int stratified::insert(int x)
{ 
  if (x == mi || x == ma) return 0;  // x already present

  if (sz == 0) 
  { mi = ma = x;
    sz++;
    return 1;
   }

  if (sz == 1)
  { // incremental construction iff sz > 2
    if ( x > mi ) 
       ma = x;
    else
       mi = x;
    sz++;
    return 1;
   }

  // default: k>1

  int inserted = 0;

  if ( x > ma )
  { int t = ma;
    ma = x;
    x = t;
   }
    
  if ( x < mi )
  { int t = mi;
    mi = x;
    x = t;
   }


  int x1 = high_bits(x);
  int x2 = low_bits(x);

  // for incremental construction

  if ( top == 0 )           
  { // allocate new structures
    top = new l_stratified; 
    bot = new b_dict;
   }          

  b_dict_item it = bot->lookup(x1);
  GenPtr p = (it) ? bot->inf(it) : 0;

  l_stratified_ptr l_bot_ptr = (l_stratified_ptr)p;

  if ( l_bot_ptr )
  {
    if ( l_bot_ptr->size() == 1 )
      inserted = l_bot_ptr->insert(x2);
    else
    {
      stratified_ptr bot_ptr;

      if ( l_bot_ptr->size() == 2 ) 
      {
        if ( !l_bot_ptr->member(x2) ) 
        {
          bot_ptr = new stratified(l_bot_ptr,down(k));
          inserted = bot_ptr->insert(x2);

          p = (GenPtr)bot_ptr;

          delete l_bot_ptr;
        }
      }
      else       // l_bot_ptr was a bot_ptr
      {
        bot_ptr = stratified_ptr(p) ;
        inserted = bot_ptr->insert(x2);
      }
    }

  }
  else                // no top entry 
  {
    l_bot_ptr = new l_stratified(x2);

    if ( top->size() <= 1 )
      top->insert(x1);
    else
    { 
      stratified_ptr ntop;

      if ( top->size() == 2 )
      { 
        ntop = new stratified(top,up(k));
        delete top;
        top = (l_stratified_ptr)ntop;
      }
      else
        ntop = (stratified_ptr)top;

      ntop->insert(x1);
    }

    bot->insert(x1,l_bot_ptr);
    inserted = 1;
  }

 if (inserted) sz++;

 return inserted;
}

// ----------------------------------------------------------
//
// del              
//
// streicht ein Element x rekursiv aus dem Baum 
//
// liefert 1, falls es gestrichen wurde
//
//         0, falls es nicht Element der Struktur war
//
// ----------------------------------------------------------

int stratified::del(int x)

{ 

  int deleted = 0;

  switch (sz)
  {

    case 0 : break;

    case 1 : if ( x == mi )
             { mi = ma = -1;
               deleted = 1;
              }
             break;

    case 2 : if ( x == mi ) 
             { mi = ma;
               deleted = 1;
              }
             if ( x == ma )
             { ma = mi;
               deleted = 1;
              }
             break;

    case 3 : /* delete incremental construction */
             { int t = min2();     /* third element */

               if ( x == mi )      /* new minimum   */
               { mi = t;
                 deleted = 1;
                }

               if ( x == ma )      /* new maximum   */
               { ma = t;
                 deleted = 1;
                }

               if ( x == t ) deleted = 1;

               if ( deleted ) /* delete stratified trees of bot  */
               {
                 bot->clear();
                 delete bot;
                 delete top;
                 bot = 0;
                 top = 0;
               }              /* incremental construction deleted */
               break;
             }         

    default: {
               l_stratified_ptr l_bot_ptr;
               stratified_ptr bot_ptr;

               if ( x == ma )                 /* delete maximum */
               { int z = max2();
                 ma = z;
                 x = z;
                }

               if ( x == mi )                /* delete minimum */
               { int z = min2();
                 mi = z;
                 x = z;
                }

               int x1 = high_bits(x);
               int x2 = low_bits(x);

               b_dict_item it = bot->lookup(x1);
               GenPtr p = (it) ? bot->inf(it) : 0;

               if (!p) return 0;    /* element not in structure */

               l_bot_ptr = (l_stratified_ptr)p;

               if ( l_bot_ptr->size() <= 2 )
               {
                 deleted = l_bot_ptr->del(x2);

                 if ( l_bot_ptr->size() == 0 )  /* delete structure */
                 {
                   delete l_bot_ptr;
  
                   if ( top->size() <= 2 )
                     top->del(x1);
                   else
                   {
                     stratified_ptr ntop = (stratified_ptr)top;
                     if ( ntop->sz == 3 )
                     { 
                       top = new l_stratified(ntop,x1);
                       delete ntop;
                     }
                     else
                       ntop->del(x1);
                   } 

                   bot->del(x1);
                 }
               }
               else                           /* stratified structure */
               {
                 bot_ptr = stratified_ptr(p);

                 if ( bot_ptr->sz == 3 )      /* change into l_stratified */
                 {
                   if ( bot_ptr->member(x2) )
                   {
                     l_bot_ptr = new l_stratified(bot_ptr,x2);
                     deleted = 1;

                     p = (GenPtr)l_bot_ptr;

                     delete bot_ptr;

                   }
                 }
                 else                               /* size >= 4 */
                   deleted = bot_ptr->del(x2);
               }

               break;
             }

  }

  if ( deleted ) sz--;

  return deleted;
}

// ----------------------------------------------------------
//
// print            
//
// druckt alle Elemente des Baumes aus            
//
// ----------------------------------------------------------

void stratified::print()
{ 
  int i = -1;
  while ((i=succ(i))>=0)
    cout << i << " ";
}

LEDA_END_NAMESPACE
