Didžiausias skaičius BST, kuris yra mažesnis arba lygus k

Didžiausias skaičius BST, kuris yra mažesnis arba lygus k

Atsižvelgiant į a šaknį Dvejetainis paieškos medis ir sveikasis skaičius k . Užduotis yra surasti didžiausias skaičius dvejetainiame paieškos medyje mažiau nei arba lygus į k, jei tokio elemento nėra, spausdinkite -1. 

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Didžiausias skaičius BST, kuris yra mažesnis nei arba lygus k-1

Išvestis: 21
Paaiškinimas: 19 ir 25 yra du artimiausi skaičiai 21, o 19 yra didžiausias skaičius, kurio reikšmė mažesnė arba lygi 21.

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Didžiausias skaičius BST, kuris yra mažesnis už arba lygus k-2

Išvestis: 3
Paaiškinimas: 3 ir 5 yra du artimiausi skaičiai 4, o 3 yra didžiausias skaičius, kurio reikšmė mažesnė arba lygi 4.

Turinio lentelė

[Naivus požiūris] Naudojant rekursiją – O(h) laikas ir O(h) erdvė

Idėja yra pradėti nuo šaknis ir palyginkite jo vertę su k. Jei mazgo reikšmė didesnė nei k, pereikite prie kairiojo pomedžio. Kitu atveju suraskite didžiausio skaičiaus reikšmę, mažesnę nei lygi k dešinysis pomedis . Jei dešinysis pomedis grąžina -1 (tai reiškia, kad tokios reikšmės nėra), tada grąžinama dabartinio mazgo reikšmė. Kitu atveju grąžinama dešiniojo pomedžio grąžinta reikšmė (nes ji bus didesnė nei dabartinio mazgo reikšmė, bet mažesnė nei lygi k).

C++
   // C++ code to find the largest value    // smaller than or equal to k using recursion   #include          using     namespace     std  ;   class     Node     {   public  :      int     data  ;      Node     *  left       *  right  ;          Node  (  int     val  ){      data     =     val  ;      left     =     nullptr  ;      right     =     nullptr  ;      }   };   // function to find max value less than k   int     findMaxFork  (  Node  *     root       int     k  )     {          // Base cases      if     (  root     ==     nullptr  )      return     -1  ;      if     (  root  ->  data     ==     k  )      return     k  ;      // If root's value is smaller      // try in right subtree      else     if     (  root  ->  data      <     k  )     {          int     x     =     findMaxFork  (  root  ->  right       k  );      if     (  x     ==     -1  )      return     root  ->  data  ;      else      return     x  ;      }      // If root's data is greater       // return value from left subtree.      return     findMaxFork  (  root  ->  left       k  );      }   int     main  ()     {          int     k     =     24  ;      // creating following BST      //      // 5      // /        // 2 12      // /  /        // 1 3 9 21      // /        // 19 25      Node  *     root     =     new     Node  (  5  );      root  ->  left     =     new     Node  (  2  );      root  ->  left  ->  left     =     new     Node  (  1  );      root  ->  left  ->  right     =     new     Node  (  3  );      root  ->  right     =     new     Node  (  12  );      root  ->  right  ->  left     =     new     Node  (  9  );      root  ->  right  ->  right     =     new     Node  (  21  );      root  ->  right  ->  right  ->  left     =     new     Node  (  19  );      root  ->  right  ->  right  ->  right     =     new     Node  (  25  );          cout      < <     findMaxFork  (  root       k  );      return     0  ;   }   
Java
   // Java code to find the largest value    // smaller than or equal to k using recursion   class   Node     {      int     data  ;      Node     left       right  ;          Node  (  int     val  )     {      data     =     val  ;      left     =     null  ;      right     =     null  ;      }   }   class   GfG     {          // function to find max value less than k      static     int     findMaxFork  (  Node     root       int     k  )     {          // Base cases      if     (  root     ==     null  )      return     -  1  ;      if     (  root  .  data     ==     k  )      return     k  ;      // If root's value is smaller      // try in right subtree      else     if     (  root  .  data      <     k  )     {      int     x     =     findMaxFork  (  root  .  right       k  );      if     (  x     ==     -  1  )      return     root  .  data  ;      else      return     x  ;      }      // If root's data is greater      // return value from left subtree.      return     findMaxFork  (  root  .  left       k  );      }      public     static     void     main  (  String  []     args  )     {      int     k     =     24  ;      // creating following BST      //      // 5      // /        // 2 12      // /  /        // 1 3 9 21      // /        // 19 25      Node     root     =     new     Node  (  5  );      root  .  left     =     new     Node  (  2  );      root  .  left  .  left     =     new     Node  (  1  );      root  .  left  .  right     =     new     Node  (  3  );      root  .  right     =     new     Node  (  12  );      root  .  right  .  left     =     new     Node  (  9  );      root  .  right  .  right     =     new     Node  (  21  );      root  .  right  .  right  .  left     =     new     Node  (  19  );      root  .  right  .  right  .  right     =     new     Node  (  25  );      System  .  out  .  println  (  findMaxFork  (  root       k  ));      }   }   
Python
   # Python code to find the largest value    # smaller than or equal to k using recursion   class   Node  :   def   __init__  (  self     val  ):   self  .  data   =   val   self  .  left   =   None   self  .  right   =   None   # function to find max value less than k   def   findMaxFork  (  root     k  ):   # Base cases   if   root   is   None  :   return   -  1   if   root  .  data   ==   k  :   return   k   # If root's value is smaller   # try in right subtree   elif   root  .  data    <   k  :   x   =   findMaxFork  (  root  .  right     k  )   if   x   ==   -  1  :   return   root  .  data   else  :   return   x   # If root's data is greater   # return value from left subtree.   return   findMaxFork  (  root  .  left     k  )   if   __name__   ==   '__main__'  :   k   =   24   # creating following BST   #   # 5   # /     # 2 12   # /  /     # 1 3 9 21   # /     # 19 25   root   =   Node  (  5  )   root  .  left   =   Node  (  2  )   root  .  left  .  left   =   Node  (  1  )   root  .  left  .  right   =   Node  (  3  )   root  .  right   =   Node  (  12  )   root  .  right  .  left   =   Node  (  9  )   root  .  right  .  right   =   Node  (  21  )   root  .  right  .  right  .  left   =   Node  (  19  )   root  .  right  .  right  .  right   =   Node  (  25  )   print  (  findMaxFork  (  root     k  ))   
C#
   // C# code to find the largest value    // smaller than or equal to k using recursion   using     System  ;   class     Node     {      public     int     data  ;      public     Node     left       right  ;          public     Node  (  int     val  )     {      data     =     val  ;      left     =     null  ;      right     =     null  ;      }   }   class     GfG     {          // function to find max value less than k      static     int     FindMaxFork  (  Node     root       int     k  )     {          // Base cases      if     (  root     ==     null  )      return     -  1  ;      if     (  root  .  data     ==     k  )      return     k  ;      // If root's value is smaller      // try in right subtree      else     if     (  root  .  data      <     k  )     {      int     x     =     FindMaxFork  (  root  .  right       k  );      if     (  x     ==     -  1  )      return     root  .  data  ;      else      return     x  ;      }      // If root's data is greater      // return value from left subtree.      return     FindMaxFork  (  root  .  left       k  );      }      static     void     Main  ()     {      int     k     =     24  ;      // creating following BST      //      // 5      // /        // 2 12      // /  /        // 1 3 9 21      // /        // 19 25      Node     root     =     new     Node  (  5  );      root  .  left     =     new     Node  (  2  );      root  .  left  .  left     =     new     Node  (  1  );      root  .  left  .  right     =     new     Node  (  3  );      root  .  right     =     new     Node  (  12  );      root  .  right  .  left     =     new     Node  (  9  );      root  .  right  .  right     =     new     Node  (  21  );      root  .  right  .  right  .  left     =     new     Node  (  19  );      root  .  right  .  right  .  right     =     new     Node  (  25  );      Console  .  WriteLine  (  FindMaxFork  (  root       k  ));      }   }   
JavaScript
   // JavaScript code to find the largest value    // smaller than or equal to k using recursion   class     Node     {      constructor  (  val  )     {      this  .  data     =     val  ;      this  .  left     =     null  ;      this  .  right     =     null  ;      }   }   // function to find max value less than k   function     findMaxFork  (  root       k  )     {          // Base cases      if     (  root     ===     null  )      return     -  1  ;      if     (  root  .  data     ===     k  )      return     k  ;      // If root's value is smaller      // try in right subtree      else     if     (  root  .  data      <     k  )     {      let     x     =     findMaxFork  (  root  .  right       k  );      if     (  x     ===     -  1  )      return     root  .  data  ;      else      return     x  ;      }      // If root's data is greater      // return value from left subtree.      return     findMaxFork  (  root  .  left       k  );   }   let     k     =     24  ;   // creating following BST   //   // 5   // /     // 2 12   // /  /     // 1 3 9 21   // /     // 19 25   let     root     =     new     Node  (  5  );   root  .  left     =     new     Node  (  2  );   root  .  left  .  left     =     new     Node  (  1  );   root  .  left  .  right     =     new     Node  (  3  );   root  .  right     =     new     Node  (  12  );   root  .  right  .  left     =     new     Node  (  9  );   root  .  right  .  right     =     new     Node  (  21  );   root  .  right  .  right  .  left     =     new     Node  (  19  );   root  .  right  .  right  .  right     =     new     Node  (  25  );   console  .  log  (  findMaxFork  (  root       k  ));   

Išvestis
21 

[Numatomas metodas] Iteracijos naudojimas – O(h) laikas ir O(1) erdvė

Idėja yra pradėti nuo šaknis ir palyginkite jo vertę su k . Jei mazgo vertė yra <= k atnaujinkite rezultato reikšmę į šaknies reikšmę ir pereikite prie teisingai kitas pomedis perkelti į paliko pomedis. Autorius iteratyviai Taikydami šią operaciją visuose mazguose galime sumažinti vietos, reikalingos rekursija krūva.

C++
   // C++ code to find the largest value    // smaller than or equal to k using recursion   #include          using     namespace     std  ;   class     Node     {   public  :      int     data  ;      Node     *  left       *  right  ;          Node  (  int     val  ){      data     =     val  ;      left     =     nullptr  ;      right     =     nullptr  ;      }   };   // function to find max value less than k   int     findMaxFork  (  Node  *     root       int     k  )     {          int     result     =     -1  ;          // Start from root and keep looking for larger       while     (  root     !=     nullptr  )     {      // If root is smaller go to right side      if     (  root  ->  data      <=     k  ){      result     =     root  ->  data  ;      root     =     root  ->  right  ;      }      // If root is greater go to left side       else      root     =     root  ->  left  ;      }          return     result  ;   }   int     main  ()     {          int     k     =     24  ;      // creating following BST      //      // 5      // /        // 2 12      // /  /        // 1 3 9 21      // /        // 19 25      Node  *     root     =     new     Node  (  5  );      root  ->  left     =     new     Node  (  2  );      root  ->  left  ->  left     =     new     Node  (  1  );      root  ->  left  ->  right     =     new     Node  (  3  );      root  ->  right     =     new     Node  (  12  );      root  ->  right  ->  left     =     new     Node  (  9  );      root  ->  right  ->  right     =     new     Node  (  21  );      root  ->  right  ->  right  ->  left     =     new     Node  (  19  );      root  ->  right  ->  right  ->  right     =     new     Node  (  25  );          cout      < <     findMaxFork  (  root       k  );      return     0  ;   }   
Java
   // Java code to find the largest value    // smaller than or equal to k using recursion   class   Node     {      int     data  ;      Node     left       right  ;          Node  (  int     val  )     {      data     =     val  ;      left     =     null  ;      right     =     null  ;      }   }   class   GfG     {          // function to find max value less than k      static     int     findMaxFork  (  Node     root       int     k  )     {      int     result     =     -  1  ;          // Start from root and keep looking for larger       while     (  root     !=     null  )     {      // If root is smaller go to right side      if     (  root  .  data      <=     k  )     {      result     =     root  .  data  ;      root     =     root  .  right  ;      }      // If root is greater go to left side       else     {      root     =     root  .  left  ;      }      }          return     result  ;      }      public     static     void     main  (  String  []     args  )     {      int     k     =     24  ;      // creating following BST      //      // 5      // /        // 2 12      // /  /        // 1 3 9 21      // /        // 19 25      Node     root     =     new     Node  (  5  );      root  .  left     =     new     Node  (  2  );      root  .  left  .  left     =     new     Node  (  1  );      root  .  left  .  right     =     new     Node  (  3  );      root  .  right     =     new     Node  (  12  );      root  .  right  .  left     =     new     Node  (  9  );      root  .  right  .  right     =     new     Node  (  21  );      root  .  right  .  right  .  left     =     new     Node  (  19  );      root  .  right  .  right  .  right     =     new     Node  (  25  );      System  .  out  .  println  (  findMaxFork  (  root       k  ));      }   }   
Python
   # Python code to find the largest value    # smaller than or equal to k using recursion   class   Node  :   def   __init__  (  self     val  ):   self  .  data   =   val   self  .  left   =   None   self  .  right   =   None   # function to find max value less than k   def   findMaxFork  (  root     k  ):   result   =   -  1   # Start from root and keep looking for larger    while   root   is   not   None  :   # If root is smaller go to right side   if   root  .  data    <=   k  :   result   =   root  .  data   root   =   root  .  right   # If root is greater go to left side    else  :   root   =   root  .  left   return   result   if   __name__   ==   '__main__'  :   k   =   24   # creating following BST   #   # 5   # /     # 2 12   # /  /     # 1 3 9 21   # /     # 19 25   root   =   Node  (  5  )   root  .  left   =   Node  (  2  )   root  .  left  .  left   =   Node  (  1  )   root  .  left  .  right   =   Node  (  3  )   root  .  right   =   Node  (  12  )   root  .  right  .  left   =   Node  (  9  )   root  .  right  .  right   =   Node  (  21  )   root  .  right  .  right  .  left   =   Node  (  19  )   root  .  right  .  right  .  right   =   Node  (  25  )   print  (  findMaxFork  (  root     k  ))   
C#
   // C# code to find the largest value    // smaller than or equal to k using recursion   using     System  ;   class     Node     {      public     int     data  ;      public     Node     left       right  ;          public     Node  (  int     val  )     {      data     =     val  ;      left     =     null  ;      right     =     null  ;      }   }   class     GfG     {          // function to find max value less than k      static     int     FindMaxFork  (  Node     root       int     k  )     {      int     result     =     -  1  ;          // Start from root and keep looking for larger       while     (  root     !=     null  )     {      // If root is smaller go to right side      if     (  root  .  data      <=     k  )     {      result     =     root  .  data  ;      root     =     root  .  right  ;      }      // If root is greater go to left side       else     {      root     =     root  .  left  ;      }      }          return     result  ;      }      static     void     Main  ()     {      int     k     =     24  ;      // creating following BST      //      // 5      // /        // 2 12      // /  /        // 1 3 9 21      // /        // 19 25      Node     root     =     new     Node  (  5  );      root  .  left     =     new     Node  (  2  );      root  .  left  .  left     =     new     Node  (  1  );      root  .  left  .  right     =     new     Node  (  3  );      root  .  right     =     new     Node  (  12  );      root  .  right  .  left     =     new     Node  (  9  );      root  .  right  .  right     =     new     Node  (  21  );      root  .  right  .  right  .  left     =     new     Node  (  19  );      root  .  right  .  right  .  right     =     new     Node  (  25  );      Console  .  WriteLine  (  FindMaxFork  (  root       k  ));      }   }   
JavaScript
   // JavaScript code to find the largest value    // smaller than or equal to k using recursion   class     Node     {      constructor  (  val  )     {      this  .  data     =     val  ;      this  .  left     =     null  ;      this  .  right     =     null  ;      }   }   // function to find max value less than k   function     findMaxFork  (  root       k  )     {      let     result     =     -  1  ;          // Start from root and keep looking for larger       while     (  root     !==     null  )     {      // If root is smaller go to right side      if     (  root  .  data      <=     k  )     {      result     =     root  .  data  ;      root     =     root  .  right  ;      }      // If root is greater go to left side       else     {      root     =     root  .  left  ;      }      }          return     result  ;   }   let     k     =     24  ;   // creating following BST   //   // 5   // /     // 2 12   // /  /     // 1 3 9 21   // /     // 19 25   let     root     =     new     Node  (  5  );   root  .  left     =     new     Node  (  2  );   root  .  left  .  left     =     new     Node  (  1  );   root  .  left  .  right     =     new     Node  (  3  );   root  .  right     =     new     Node  (  12  );   root  .  right  .  left     =     new     Node  (  9  );   root  .  right  .  right     =     new     Node  (  21  );   root  .  right  .  right  .  left     =     new     Node  (  19  );   root  .  right  .  right  .  right     =     new     Node  (  25  );   console  .  log  (  findMaxFork  (  root       k  ));   

Išvestis
21 
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