Kloonaa linkitetty lista seuraavalla ja satunnaisella osoittimella O(1)-avaruudessa

Kloonaa linkitetty lista seuraavalla ja satunnaisella osoittimella O(1)-avaruudessa

Koska a linkitetty lista kooltaan N jossa jokaisella solmulla on kaksi linkkiä: seuraava osoitin osoittaa seuraavaan solmuun ja satunnainen osoitin mihin tahansa luettelon satunnaiseen solmuun. Tehtävänä on luoda tästä linkitetystä listasta klooni O(1)-avaruuteen eli ilman ylimääräistä tilaa. 

Esimerkkejä:  

Syöte: Alla linkitetyn luettelon pää

Kloonaa linkitetty lista seuraavalla ja satunnaisella osoittimella O(1)-avaruudessa

Lähtö: Uusi linkitetty luettelo, joka on identtinen alkuperäisen luettelon kanssa.

[Odotettu lähestymistapa] lisäämällä solmut paikoilleen – O(3n) aika ja O(1) avaruus

Ajatuksena on luoda solmun kaksoiskappale ja erilliseen hash-taulukkoon tallentamisen sijaan voimme lisätä sen alkuperäisen solmun ja seuraavan solmun väliin. Nyt meillä on uusia solmuja vaihtoehtoisissa paikoissa. Nyt a solmu X sen kaksoiskappale tulee olemaan X-> seuraavaksi ja kaksoiskappaleen satunnaisen osoittimen tulee osoittaa X->satunnainen->seuraava (koska se on kopio X-> satunnainen ). Joten iteroi koko linkitetty luettelo päivittääksesi kaikkien kloonattujen solmujen satunnaisen osoittimen ja toista sitten uudelleen erottaaksesi alkuperäinen linkitetty luettelo ja kloonattu linkitetty luettelo.

Toteuta idea noudattamalla alla mainittuja vaiheita:

  • Luo kopio kohteesta solmu 1 ja aseta se väliin solmu 1 ja solmu 2 luo kopio alkuperäisessä linkitetyssä luettelossa solmu 2 ja aseta se väliin 2 nd ja 3 rd solmu ja niin edelleen. Lisää kopio N:stä N:n perään th solmu
  • Yhdistä kloonisolmu päivittämällä satunnaiset osoittimet.
  • Erota kloonattu linkitetty luettelo alkuperäisestä luettelosta päivittämällä seuraavat osoittimet.

Kloonaa linkitetty lista seuraavalla ja satunnaisella osoittimella O(1)-avaruudessa


Alla on toteutus, jos yllä oleva lähestymistapa: 

C++
   // C++ code to Clone a linked list with next and random   // pointer by Inserting Nodes In-place   #include          using     namespace     std  ;   struct     Node     {      int     data  ;      Node     *  next       *  random  ;      Node  (  int     x  )     {      data     =     x  ;      next     =     random     =     NULL  ;      }   };   Node  *     cloneLinkedList  (  Node  *     head  )     {      if     (  head     ==     NULL  )     {      return     NULL  ;      }          // Create new nodes and insert them next to       // the original nodes      Node  *     curr     =     head  ;      while     (  curr     !=     NULL  )     {      Node  *     newNode     =     new     Node  (  curr  ->  data  );      newNode  ->  next     =     curr  ->  next  ;      curr  ->  next     =     newNode  ;      curr     =     newNode  ->  next  ;      }          // Set the random pointers of the new nodes      curr     =     head  ;      while     (  curr     !=     NULL  )     {      if     (  curr  ->  random     !=     NULL  )      curr  ->  next  ->  random     =     curr  ->  random  ->  next  ;      curr     =     curr  ->  next  ->  next  ;      }          // Separate the new nodes from the original nodes      curr     =     head  ;      Node  *     clonedHead     =     head  ->  next  ;      Node  *     clone     =     clonedHead  ;      while     (  clone  ->  next     !=     NULL  )     {          // Update the next nodes of original node       // and cloned node      curr  ->  next     =     curr  ->  next  ->  next  ;      clone  ->  next     =     clone  ->  next  ->  next  ;          // Move pointers of original as well as       // cloned linked list to their next nodes      curr     =     curr  ->  next  ;      clone     =     clone  ->  next  ;      }      curr  ->  next     =     NULL  ;      clone  ->  next     =     NULL  ;          return     clonedHead  ;   }   // Function to print the linked list   void     printList  (  Node  *     head  )     {      while     (  head     !=     NULL  )     {      cout      < <     head  ->  data      < <     '('  ;      if  (  head  ->  random  )      cout      < <     head  ->  random  ->  data      < <     ')'  ;      else         cout      < <     'null'      < <     ')'  ;          if  (  head  ->  next     !=     NULL  )      cout      < <     ' -> '  ;      head     =     head  ->  next  ;      }      cout      < <     endl  ;   }   int     main  ()     {          // Creating a linked list with random pointer      Node  *     head     =     new     Node  (  1  );      head  ->  next     =     new     Node  (  2  );      head  ->  next  ->  next     =     new     Node  (  3  );      head  ->  next  ->  next  ->  next     =     new     Node  (  4  );      head  ->  next  ->  next  ->  next  ->  next     =     new     Node  (  5  );      head  ->  random     =     head  ->  next  ->  next  ;      head  ->  next  ->  random     =     head  ;      head  ->  next  ->  next  ->  random     =     head  ->  next  ->  next  ->  next  ->  next  ;      head  ->  next  ->  next  ->  next  ->  random     =     head  ->  next  ->  next  ;      head  ->  next  ->  next  ->  next  ->  next  ->  random     =     head  ->  next  ;          // Print the original list      cout      < <     'Original linked list:  n  '  ;      printList  (  head  );          // Function call      Node  *     clonedList     =     cloneLinkedList  (  head  );          cout      < <     'Cloned linked list:  n  '  ;      printList  (  clonedList  );          return     0  ;   }   
Java
   // Java code to Clone a linked list with next and random   // pointer by Inserting Nodes In-place   class   Node     {      int     data  ;      Node     next       random  ;          Node  (  int     x  )     {      data     =     x  ;      next     =     random     =     null  ;      }   }   class   GfG     {          // Function to clone the linked list      static     Node     cloneLinkedList  (  Node     head  )     {      if     (  head     ==     null  )     {      return     null  ;      }          // Create new nodes and insert them next to the original nodes      Node     curr     =     head  ;      while     (  curr     !=     null  )     {      Node     newNode     =     new     Node  (  curr  .  data  );      newNode  .  next     =     curr  .  next  ;      curr  .  next     =     newNode  ;      curr     =     newNode  .  next  ;      }          // Set the random pointers of the new nodes      curr     =     head  ;      while     (  curr     !=     null  )     {      if     (  curr  .  random     !=     null  )     {      curr  .  next  .  random     =     curr  .  random  .  next  ;      }      curr     =     curr  .  next  .  next  ;      }          // Separate the new nodes from the original nodes      curr     =     head  ;      Node     clonedHead     =     head  .  next  ;      Node     clone     =     clonedHead  ;      while     (  clone  .  next     !=     null  )     {      // Update the next nodes of original node      // and cloned node      curr  .  next     =     curr  .  next  .  next  ;      clone  .  next     =     clone  .  next  .  next  ;          // Move pointers of original and cloned      // linked list to their next nodes      curr     =     curr  .  next  ;      clone     =     clone  .  next  ;      }      curr  .  next     =     null  ;      clone  .  next     =     null  ;          return     clonedHead  ;      }          // Function to print the linked list      public     static     void     printList  (  Node     head  )     {      while     (  head     !=     null  )     {      System  .  out  .  print  (  head  .  data     +     '('  );      if     (  head  .  random     !=     null  )     {      System  .  out  .  print  (  head  .  random  .  data  );      }     else     {      System  .  out  .  print  (  'null'  );      }      System  .  out  .  print  (  ')'  );          if     (  head  .  next     !=     null  )     {      System  .  out  .  print  (  ' -> '  );      }      head     =     head  .  next  ;      }      System  .  out  .  println  ();      }          public     static     void     main  (  String  []     args  )     {          // Creating a linked list with random pointer      Node     head     =     new     Node  (  1  );      head  .  next     =     new     Node  (  2  );      head  .  next  .  next     =     new     Node  (  3  );      head  .  next  .  next  .  next     =     new     Node  (  4  );      head  .  next  .  next  .  next  .  next     =     new     Node  (  5  );      head  .  random     =     head  .  next  .  next  ;      head  .  next  .  random     =     head  ;      head  .  next  .  next  .  random     =     head  .  next  .  next  .  next  .  next  ;      head  .  next  .  next  .  next  .  random     =     head  .  next  .  next  ;      head  .  next  .  next  .  next  .  next  .  random     =     head  .  next  ;          // Print the original list      System  .  out  .  println  (  'Original linked list:'  );      printList  (  head  );          // Function call      Node     clonedList     =     cloneLinkedList  (  head  );          System  .  out  .  println  (  'Cloned linked list:'  );      printList  (  clonedList  );      }   }   
Python
   # Python code to Clone a linked list with next and random   # pointer by Inserting Nodes In-place   class   Node  :   def   __init__  (  self     x  ):   self  .  data   =   x   self  .  next   =   None   self  .  random   =   None   # Function to clone the linked list   def   clone_linked_list  (  head  ):   if   head   is   None  :   return   None   # Create new nodes and insert them next to    # the original nodes   curr   =   head   while   curr   is   not   None  :   new_node   =   Node  (  curr  .  data  )   new_node  .  next   =   curr  .  next   curr  .  next   =   new_node   curr   =   new_node  .  next   # Set the random pointers of the new nodes   curr   =   head   while   curr   is   not   None  :   if   curr  .  random   is   not   None  :   curr  .  next  .  random   =   curr  .  random  .  next   curr   =   curr  .  next  .  next   # Separate the new nodes from the original nodes   curr   =   head   cloned_head   =   head  .  next   clone   =   cloned_head   while   clone  .  next   is   not   None  :   # Update the next nodes of original node    # and cloned node   curr  .  next   =   curr  .  next  .  next   clone  .  next   =   clone  .  next  .  next   # Move pointers of original as well as    # cloned linked list to their next nodes   curr   =   curr  .  next   clone   =   clone  .  next   curr  .  next   =   None   clone  .  next   =   None   return   cloned_head   # Function to print the linked list   def   print_list  (  head  ):   while   head   is   not   None  :   print  (  f  '  {  head  .  data  }  ('     end  =  ''  )   if   head  .  random  :   print  (  f  '  {  head  .  random  .  data  }  )'     end  =  ''  )   else  :   print  (  'null)'     end  =  ''  )   if   head  .  next   is   not   None  :   print  (  ' -> '     end  =  ''  )   head   =   head  .  next   print  ()   if   __name__   ==   '__main__'  :   # Creating a linked list with random pointer   head   =   Node  (  1  )   head  .  next   =   Node  (  2  )   head  .  next  .  next   =   Node  (  3  )   head  .  next  .  next  .  next   =   Node  (  4  )   head  .  next  .  next  .  next  .  next   =   Node  (  5  )   head  .  random   =   head  .  next  .  next   head  .  next  .  random   =   head   head  .  next  .  next  .  random   =   head  .  next  .  next  .  next  .  next   head  .  next  .  next  .  next  .  random   =   head  .  next  .  next   head  .  next  .  next  .  next  .  next  .  random   =   head  .  next   # Print the original list   print  (  'Original linked list:'  )   print_list  (  head  )   # Function call   cloned_list   =   clone_linked_list  (  head  )   print  (  'Cloned linked list:'  )   print_list  (  cloned_list  )   
C#
   // C# code to Clone a linked list with next and random   // pointer by Inserting Nodes In-place   using     System  ;   using     System.Collections.Generic  ;   public     class     Node     {      public     int     Data  ;      public     Node     next       Random  ;      public     Node  (  int     x  )     {      Data     =     x  ;      next     =     Random     =     null  ;      }   }   class     GfG     {      static     Node     CloneLinkedList  (  Node     head  )     {      if     (  head     ==     null  )      return     null  ;      // Create new nodes and insert them next to       // the original nodes      Node     curr     =     head  ;      while     (  curr     !=     null  )     {      Node     newNode     =     new     Node  (  curr  .  Data  );      newNode  .  next     =     curr  .  next  ;      curr  .  next     =     newNode  ;      curr     =     newNode  .  next  ;      }      // Set the random pointers of the new nodes      curr     =     head  ;      while     (  curr     !=     null  )     {      if     (  curr  .  Random     !=     null  )      curr  .  next  .  Random     =     curr  .  Random  .  next  ;      curr     =     curr  .  next  .  next  ;      }      // Separate the new nodes from the original nodes      curr     =     head  ;      Node     clonedHead     =     head  .  next  ;      Node     clone     =     clonedHead  ;      while     (  clone  .  next     !=     null  )     {          // Update the next nodes of original node       // and cloned node      curr  .  next     =     curr  .  next  .  next  ;      clone  .  next     =     clone  .  next  .  next  ;      // Move pointers of original as well as       // cloned linked list to their next nodes      curr     =     curr  .  next  ;      clone     =     clone  .  next  ;      }      curr  .  next     =     null  ;      clone  .  next     =     null  ;      return     clonedHead  ;      }      // Function to print the linked list      static     void     PrintList  (  Node     head  )     {      while     (  head     !=     null  )     {      Console  .  Write  (  head  .  Data     +     '('  );      if     (  head  .  Random     !=     null  )      Console  .  Write  (  head  .  Random  .  Data     +     ')'  );      else      Console  .  Write  (  'null)'  );          if     (  head  .  next     !=     null  )      Console  .  Write  (  ' -> '  );      head     =     head  .  next  ;      }      Console  .  WriteLine  ();      }      public     static     void     Main  ()     {          // Creating a linked list with random pointer      Node     head     =     new     Node  (  1  );      head  .  next     =     new     Node  (  2  );      head  .  next  .  next     =     new     Node  (  3  );      head  .  next  .  next  .  next     =     new     Node  (  4  );      head  .  next  .  next  .  next  .  next     =     new     Node  (  5  );      head  .  Random     =     head  .  next  .  next  ;      head  .  next  .  Random     =     head  ;      head  .  next  .  next  .  Random     =     head  .  next  .  next  .  next  .  next  ;      head  .  next  .  next  .  next  .  Random     =     head  .  next  .  next  ;      head  .  next  .  next  .  next  .  next  .  Random     =     head  .  next  ;      // Print the original list      Console  .  WriteLine  (  'Original linked list:'  );      PrintList  (  head  );      Node     clonedList     =     CloneLinkedList  (  head  );      Console  .  WriteLine  (  'Cloned linked list:'  );      PrintList  (  clonedList  );      }   }   
JavaScript
   // JavaScript code to Clone a linked list with next and random   // pointer by Inserting Nodes In-place   class     Node     {      constructor  (  data  )     {      this  .  data     =     data  ;      this  .  next     =     null  ;      this  .  random     =     null  ;      }   }   function     cloneLinkedList  (  head  )     {      if     (  head     ===     null  )     {      return     null  ;      }      // Create new nodes and insert them next to the       // original nodes      let     curr     =     head  ;      while     (  curr     !==     null  )     {      let     newNode     =     new     Node  (  curr  .  data  );      newNode  .  next     =     curr  .  next  ;      curr  .  next     =     newNode  ;      curr     =     newNode  .  next  ;      }      // Set the random pointers of the new nodes      curr     =     head  ;      while     (  curr     !==     null  )     {      if     (  curr  .  random     !==     null  )     {      curr  .  next  .  random     =     curr  .  random  .  next  ;      }      curr     =     curr  .  next  .  next  ;      }      // Separate the new nodes from the original nodes      curr     =     head  ;      let     clonedHead     =     head  .  next  ;      let     clone     =     clonedHead  ;      while     (  clone  .  next     !==     null  )     {          // Update the next nodes of original node and cloned node      curr  .  next     =     curr  .  next  .  next  ;      clone  .  next     =     clone  .  next  .  next  ;      // Move pointers of original as well as cloned      // linked list to their next nodes      curr     =     curr  .  next  ;      clone     =     clone  .  next  ;      }      curr  .  next     =     null  ;      clone  .  next     =     null  ;      return     clonedHead  ;   }   // Function to print the linked list   function     printList  (  head  )     {      let     result     =     ''  ;      while     (  head     !==     null  )     {      result     +=     head  .  data     +     '('  ;      result     +=     head  .  random     ?     head  .  random  .  data     :     'null'  ;      result     +=     ')'  ;      if     (  head  .  next     !==     null  )     {      result     +=     ' -> '  ;      }      head     =     head  .  next  ;      }      console  .  log  (  result  );   }   // Creating a linked list with random pointer   let     head     =     new     Node  (  1  );   head  .  next     =     new     Node  (  2  );   head  .  next  .  next     =     new     Node  (  3  );   head  .  next  .  next  .  next     =     new     Node  (  4  );   head  .  next  .  next  .  next  .  next     =     new     Node  (  5  );   head  .  random     =     head  .  next  .  next  ;   head  .  next  .  random     =     head  ;   head  .  next  .  next  .  random     =     head  .  next  .  next  .  next  .  next  ;   head  .  next  .  next  .  next  .  random     =     head  .  next  .  next  ;   head  .  next  .  next  .  next  .  next  .  random     =     head  .  next  ;   // Print the original list   console  .  log  (  'Original linked list:'  );   printList  (  head  );   let     clonedList     =     cloneLinkedList  (  head  );   console  .  log  (  'Cloned linked list:'  );   printList  (  clonedList  );   

Lähtö
Original linked list: 1(3) -> 2(1) -> 3(5) -> 4(3) -> 5(2) Cloned linked list: 1(3) -> 2(1) -> 3(5) -> 4(3) -> 5(2)  

Aika monimutkaisuus: O(3n) koska käymme linkitetyn luettelon läpi kolme kertaa.
Aputila: O(1) koska tallennamme kaikki kloonatut solmut itse alkuperäiseen linkitettyyn luetteloon, lisätilaa ei tarvita.

Luo tietokilpailu