Laimingas skaičius

Laimingas skaičius
Išbandykite GfG praktikoje

Skaičius vadinamas laimingu, jei po žingsnių sekos jis veda į 1, kai kiekvienas žingsnio numeris pakeičiamas jo skaitmens kvadratų suma, ty jei pradedame nuo laimingo skaičiaus ir nuolat keičiame jį skaitmenimis, kurių kvadratinė suma pasiekiame 1. 

Pavyzdžiai:  

 Input: n = 19   
Output: True
19 is Happy Number
1^2 + 9^2 = 82
8^2 + 2^2 = 68
6^2 + 8^2 = 100
1^2 + 0^2 + 0^2 = 1
As we reached to 1 19 is a Happy Number.

Input: n = 20
Output: False

Skaičius nebus laimingas skaičius, kai jis savo sekoje padaro kilpą, ty paliečia skaičių iš eilės, kuri jau buvo paliesta. Taigi norėdami patikrinti, ar skaičius yra laimingas, ar ne, galime išlaikyti rinkinį, jei tas pats skaičius pasikartoja, pažymime rezultatą kaip nelaimingą. Paprasta aukščiau pateikto metodo funkcija gali būti parašyta taip, kaip nurodyta toliau –  

C++
   // method return true if n is Happy Number   int     numSquareSum  (  int     n  )     {      int     num     =     0  ;      while     (  n     !=     0  )     {      int     digit     =     n     %     10  ;      num     +=     digit     *     digit  ;      n     /=     10  ;      }      return     num  ;   }   int     isHappyNumber  (  int     n  )   {      set   <  int  >     st  ;      while     (  1  )      {      n     =     numSquareSum  (  n  );      if     (  n     ==     1  )      return     true  ;      if     (  st  .  find  (  n  )     !=     st  .  end  ())      return     false  ;      st  .  insert  (  n  );      }   }   
Java
   // method return true if n is Happy Number   public     static     int     numSquareSum  (  int     n  )   {      int     num     =     0  ;      while     (  n     !=     0  )     {      int     digit     =     n     %     10  ;      num     +=     digit     *     digit  ;      n     /=     10  ;      }      return     num  ;   }   static     boolean     isHappyNumber  (  int     n  )   {      HashSet   <  Integer  >     st     =     new     HashSet   <>  ();      while     (  true  )     {      n     =     numSquareSum  (  n  );      if     (  n     ==     1  )      return     true  ;      if     (  st  .  contains  (  n  ))      return     false  ;      st  .  add  (  n  );      }   }   // This code is contributed by Princi Singh   
Python
   # method return true if n is Happy Number   def   numSquareSum  (  n  ):   num   =   0   while  (  n  ):   digit   =   n   %   10   num   =   num   +   digit  *  digit   n   =   n   //   10   return   num   def   isHappyNumber  (  n  ):   st   =   set  ()   while   (  1  ):   n   =   numSquareSum  (  n  )   if   (  n   ==   1  ):   return   True   if   n   not   in   st  :   return   False   st  .  insert  (  n  )   
C#
   // Method return true if n is Happy Number   static     int     numSquareSum  (  int     n  )   {      int     num     =     0  ;      while     (  n     !=     0  )     {      int     digit     =     n     %     10  ;      num     +=     digit     *     digit  ;      n     /=     10  ;      }      return     num  ;   }   static     int     isHappyNumber  (  int     n  )   {      HashSet   <  int  >     st     =     new     HashSet   <>  ();      while     (  1  )     {      n     =     numSquareSum  (  n  );      if     (  n     ==     1  )      return     true  ;      if     (  st  .  Contains  (  n  ))      return     false  ;      st  .  Add  (  n  );      }   }   // This code is contributed by 29AjayKumar   
JavaScript
    <  script  >   // method return true if n is Happy Number      function     numSquareSum  (  n  )     {      let     num     =     0  ;      while     (  n     !==     0  )     {      let     digit     =     n     %     10  ;      num     +=     digit     *     digit  ;      n     =     Math  .  floor  (  n     /     10  );      }      return     num  ;      }      let     st     =     new     Set  ();      while     (  1  )      {      n     =     numSquareSum  (  n  );      if     (  n     ==     1  )      return     true  ;      if     (  st  .  has  (  n  ))      return     false  ;      st  .  add  (  n  );      }   }   //This code is contributed by Mayank Tyagi    <  /script>   

Sudėtingumo analizė:

Laiko sudėtingumas: O(n*log(n)). 
Pagalbinė erdvė: O(n), nes saugojimui naudojamas papildomas rinkinys

Šią problemą galime išspręsti nenaudodami papildomos vietos, o ši technika gali būti naudojama ir kai kuriose kitose panašiose problemose. Jei kiekvieną skaičių traktuosime kaip mazgą, o pakeitimą kvadratinės sumos skaitmeniu kaip nuorodą, tada ši problema yra tokia pati kaip kilpos radimas nuorodų sąraše

Taigi, kaip siūlomas sprendimas iš pirmiau pateiktos nuorodos, mes išlaikysime du skaičius lėtus ir greitus, tiek inicijavimas iš nurodyto skaičiaus lėtas keičiamas po vieną žingsnį, o greitas keičiamas dviem žingsniais vienu metu. Jei jie susitinka 1, tada nurodytas skaičius yra laimingas skaičius, kitaip ne.  

C++
   // C++ program to check a number is a Happy number or not   #include          using     namespace     std  ;   // Utility method to return sum of square of digit of n   int     numSquareSum  (  int     n  )   {      int     squareSum     =     0  ;      while     (  n  )     {      squareSum     +=     (  n     %     10  )     *     (  n     %     10  );      n     /=     10  ;      }      return     squareSum  ;   }   // method return true if n is Happy number   bool     isHappynumber  (  int     n  )   {      int     slow       fast  ;      // initialize slow and fast by n      slow     =     fast     =     n  ;      do     {      // move slow number by one iteration      slow     =     numSquareSum  (  slow  );      // move fast number by two iteration      fast     =     numSquareSum  (  numSquareSum  (  fast  ));      }     while     (  slow     !=     fast  );      // if both number meet at 1 then return true      return     (  slow     ==     1  );   }   // Driver code to test above methods   int     main  ()   {      int     n     =     13  ;      if     (  isHappynumber  (  n  ))      cout      < <     n      < <     ' is a Happy number  n  '  ;      else      cout      < <     n      < <     ' is not a Happy number  n  '  ;   }   // This code is contributed by divyeshrabadiya07   
C
   // C program to check a number is a Happy number or not   #include         #include         // Utility method to return sum of square of digit of n   int     numSquareSum  (  int     n  )   {      int     squareSum     =     0  ;      while     (  n  )     {      squareSum     +=     (  n     %     10  )     *     (  n     %     10  );      n     /=     10  ;      }      return     squareSum  ;   }   // method return true if n is Happy number   bool     isHappynumber  (  int     n  )   {      int     slow       fast  ;      // initialize slow and fast by n      slow     =     fast     =     n  ;      do     {      // move slow number by one iteration      slow     =     numSquareSum  (  slow  );      // move fast number by two iteration      fast     =     numSquareSum  (  numSquareSum  (  fast  ));      }     while     (  slow     !=     fast  );      // if both number meet at 1 then return true      return     (  slow     ==     1  );   }   // Driver code to test above methods   int     main  ()   {      int     n     =     13  ;      if     (  isHappynumber  (  n  ))      printf  (  '%d is a Happy number  n  '       n  );      else      printf  (  '%d is not a Happy number  n  '       n  );   }   // This code is contributed by Sania Kumari Gupta   // (kriSania804)   
Java
   // Java program to check a number is a Happy   // number or not   class   GFG     {       // Utility method to return sum of square of   // digit of n   static     int     numSquareSum  (  int     n  )   {      int     squareSum     =     0  ;      while     (  n  !=     0  )      {      squareSum     +=     (  n     %     10  )     *     (  n     %     10  );      n     /=     10  ;      }      return     squareSum  ;   }       // method return true if n is Happy number   static     boolean     isHappynumber  (  int     n  )   {      int     slow       fast  ;          // initialize slow and fast by n      slow     =     fast     =     n  ;      do      {      // move slow number      // by one iteration      slow     =     numSquareSum  (  slow  );          // move fast number      // by two iteration      fast     =     numSquareSum  (  numSquareSum  (  fast  ));          }      while     (  slow     !=     fast  );          // if both number meet at 1      // then return true      return     (  slow     ==     1  );   }       // Driver code to test above methods   public     static     void     main  (  String  []     args  )   {      int     n     =     13  ;      if     (  isHappynumber  (  n  ))      System  .  out  .  println  (  n     +         ' is a Happy number'  );      else      System  .  out  .  println  (  n     +         ' is not a Happy number'  );   }   }   
Python
   # Python3 program to check if a number is a Happy number or not   # Utility method to return the sum of squares of digits of n   def   num_square_sum  (  n  ):   square_sum   =   0   while   n  :   square_sum   +=   (  n   %   10  )   **   2   n   //=   10   return   square_sum   # Method returns True if n is a Happy number   def   is_happy_number  (  n  ):   # Initialize slow and fast pointers   slow   =   n   fast   =   n   while   True  :   # Move slow pointer by one iteration   slow   =   num_square_sum  (  slow  )   # Move fast pointer by two iterations   fast   =   num_square_sum  (  num_square_sum  (  fast  ))   if   slow   !=   fast  :   continue   else  :   break   # If both pointers meet at 1 then return True   return   slow   ==   1   # Driver Code   n   =   13   if   is_happy_number  (  n  ):   print  (  n     'is a Happy number'  )   else  :   print  (  n     'is not a Happy number'  )   
C#
   // C# program to check a number   // is a Happy number or not   using     System  ;   class     GFG     {   // Utility method to return    // sum of square of digit of n   static     int     numSquareSum  (  int     n  )   {      int     squareSum     =     0  ;      while     (  n  !=     0  )      {      squareSum     +=     (  n     %     10  )     *         (  n     %     10  );      n     /=     10  ;      }      return     squareSum  ;   }   // method return true if   // n is Happy number   static     bool     isHappynumber  (  int     n  )   {      int     slow       fast  ;      // initialize slow and      // fast by n      slow     =     fast     =     n  ;      do      {          // move slow number      // by one iteration      slow     =     numSquareSum  (  slow  );      // move fast number      // by two iteration      fast     =     numSquareSum  (  numSquareSum  (  fast  ));      }      while     (  slow     !=     fast  );      // if both number meet at 1      // then return true      return     (  slow     ==     1  );   }   // Driver code   public     static     void     Main  ()   {      int     n     =     13  ;      if     (  isHappynumber  (  n  ))      Console  .  WriteLine  (  n     +         ' is a Happy number'  );      else      Console  .  WriteLine  (  n     +         ' is not a Happy number'  );   }   }   // This code is contributed by anuj_67.   
JavaScript
    <  script  >   // Javascript program to check a number is a Happy   // number or not   // Utility method to return sum of square of   // digit of n   function     numSquareSum  (  n  )   {      var     squareSum     =     0  ;      while     (  n  !=     0  )      {      squareSum     +=     (  n     %     10  )     *     (  n     %     10  );      n     =     parseInt  (  n  /  10  );      }      return     squareSum  ;   }       // method return true if n is Happy number   function     isHappynumber  (  n  )   {      var     slow       fast  ;          // initialize slow and fast by n      slow     =     fast     =     n  ;      do      {      // move slow number      // by one iteration      slow     =     numSquareSum  (  slow  );          // move fast number      // by two iteration      fast     =     numSquareSum  (  numSquareSum  (  fast  ));          }      while     (  slow     !=     fast  );          // if both number meet at 1      // then return true      return     (  slow     ==     1  );   }       // Driver code to test above methods   var     n     =     13  ;   if     (  isHappynumber  (  n  ))      document  .  write  (  n     +         ' is a Happy number'  );   else      document  .  write  (  n     +         ' is not a Happy number'  );       // This code contributed by Princi Singh     <  /script>   
PHP
      // PHP program to check a number   // is a Happy number or not   // Utility method to return    // sum of square of digit of n   function   numSquareSum  (   $n  )   {   $squareSum   =   0  ;   while   (  $n  )   {   $squareSum   +=   (  $n   %   10  )   *   (  $n   %   10  );   $n   /=   10  ;   }   return   $squareSum  ;   }   // method return true if   // n is Happy number   function   isHappynumber  (   $n  )   {   $slow  ;   $fast  ;   // initialize slow    // and fast by n   $slow   =   $n  ;   $fast   =   $n  ;   do   {   // move slow number   // by one iteration   $slow   =   numSquareSum  (  $slow  );   // move fast number   // by two iteration   $fast   =   numSquareSum  (  numSquareSum  (  $fast  ));   }   while   (  $slow   !=   $fast  );   // if both number meet at 1    // then return true   return   (  $slow   ==   1  );   }   // Driver Code   $n   =   13  ;   if   (  isHappynumber  (  $n  ))   echo   $n      ' is a Happy number  n  '  ;   else   echo   n      ' is not a Happy number  n  '  ;   // This code is contributed by anuj_67.   ?>   

Išvestis:  

 13 is a Happy Number  

Sudėtingumo analizė:

Laiko sudėtingumas: O(n*log(n)).
Pagalbinė erdvė: O(1). 


Kitas būdas išspręsti šią problemą nenaudojant papildomos vietos.
Skaičius negali būti laimingas skaičius jei bet kuriame žingsnyje gautų skaitmenų kvadratų suma yra vienaženklis skaičius, išskyrus 1 arba 7 . Taip yra todėl, kad 1 ir 7 yra vieninteliai vienženkliai laimingi skaičiai. Naudodami šią informaciją galime sukurti metodą, kaip parodyta toliau pateiktame kode - 

C++
   // C++ program to check if a number is a Happy number or   // not.   #include          using     namespace     std  ;   // Method - returns true if the input is a happy number else   // returns false   bool     isHappynumber  (  int     n  )   {      int     sum     =     n       x     =     n  ;      // This loop executes till the sum of square of digits      // obtained is not a single digit number      while     (  sum     >     9  )     {      sum     =     0  ;      // This loop finds the sum of square of digits      while     (  x     >     0  )     {      int     d     =     x     %     10  ;      sum     +=     d     *     d  ;      x     /=     10  ;      }      x     =     sum  ;      }      if     (  sum     ==     7     ||     sum     ==     1  )      return     true  ;      return     false  ;   }   int     main  ()   {      int     n     =     13  ;      if     (  isHappynumber  (  n  ))      cout      < <     n      < <     ' is a Happy number'  ;      else      cout      < <     n      < <     ' is not a Happy number'  ;      return     0  ;   }   // This code is contributed by Sania Kumari Gupta   
C
   // C program to check if a number is a Happy number or   // not.   #include         #include         // Method - returns true if the input is a happy number else   // returns false   bool     isHappynumber  (  int     n  )   {      int     sum     =     n       x     =     n  ;      // This loop executes till the sum of square of digits      // obtained is not a single digit number      while     (  sum     >     9  )     {      sum     =     0  ;      // This loop finds the sum of square of digits      while     (  x     >     0  )     {      int     d     =     x     %     10  ;      sum     +=     d     *     d  ;      x     /=     10  ;      }      x     =     sum  ;      }      if     (  sum     ==     7     ||     sum     ==     1  )      return     true  ;      return     false  ;   }   int     main  ()   {      int     n     =     13  ;      if     (  isHappynumber  (  n  ))      printf  (  '%d is a Happy number'       n  );      else      printf  (  '%d is not a Happy number'       n  );      return     0  ;   }   // This code is contributed by Sania Kumari Gupta   
Java
   // This code is contributed by Vansh Sodhi.   // Java program to check if a number is a Happy number or   // not.   class   GFG     {      // method - returns true if the input is a happy      // number else returns false      static     boolean     isHappynumber  (  int     n  )      {      int     sum     =     n       x     =     n  ;      // this loop executes till the sum of square of      // digits obtained is not a single digit number      while     (  sum     >     9  )     {      sum     =     0  ;      // this loop finds the sum of square of digits      while     (  x     >     0  )     {      int     d     =     x     %     10  ;      sum     +=     d     *     d  ;      x     /=     10  ;      }      x     =     sum  ;      }      if     (  sum     ==     1     ||     sum     ==     7  )      return     true  ;      return     false  ;      }      // Driver code      public     static     void     main  (  String  []     args  )      {      int     n     =     13  ;      if     (  isHappynumber  (  n  ))      System  .  out  .  println  (  n     +     ' is a Happy number'  );      else      System  .  out  .  println  (  n      +     ' is not a Happy number'  );      }   }   
Python
   # Python3 program to check if a number is a Happy number or not.   # Method - returns true if the input is   # a happy number else returns false   def   isHappynumber  (  n  ):   Sum     x   =   n     n   # This loop executes till the sum   # of square of digits obtained is   # not a single digit number   while   Sum   >   9  :   Sum   =   0   # This loop finds the sum of   # square of digits   while   x   >   0  :   d   =   x   %   10   Sum   +=   d   *   d   x   =   int  (  x   /   10  )   x   =   Sum   if   Sum   ==   1   or   Sum   ==   7  :   return   True   return   False   n   =   13   if   isHappynumber  (  n  ):   print  (  n     'is a Happy number'  )   else  :   print  (  n     'is not a Happy number'  )   # This code is contributed by mukesh07.   
C#
   // C# program to check if a number   // is a Happy number or not.   using     System  ;   class     GFG     {      // Method - returns true if the input is      // a happy number else returns false      static     bool     isHappynumber  (  int     n  )      {      int     sum     =     n       x     =     n  ;      // This loop executes till the sum      // of square of digits obtained is      // not a single digit number      while     (  sum     >     9  )     {      sum     =     0  ;      // This loop finds the sum of      // square of digits      while     (  x     >     0  )     {      int     d     =     x     %     10  ;      sum     +=     d     *     d  ;      x     /=     10  ;      }      x     =     sum  ;      }      if     (  sum     ==     1     ||     sum     ==     7  )      return     true  ;      return     false  ;      }      // Driver code      public     static     void     Main  (  String  []     args  )      {      int     n     =     13  ;      if     (  isHappynumber  (  n  ))      Console  .  WriteLine  (  n     +     ' is a Happy number'  );      else      Console  .  WriteLine  (  n     +     ' is not a Happy number'  );      }   }   // This code is contributed by 29AjayKumar   
JavaScript
    <  script  >   // This code is contributed by Vansh Sodhi.   // javascript program to check if a number is a Happy number or not.      // method - returns true if the input is a happy      // number else returns false      function     isHappynumber  (  n  )      {      var     sum     =     n       x     =     n  ;      // this loop executes till the sum of square of      // digits obtained is not a single digit number      while  (  sum     >     9  )         {      sum     =     0  ;      // this loop finds the sum of square of digits      while     (  x     >     0  )         {      var     d     =     x     %     10  ;      sum     +=     d     *     d  ;      x     /=     10  ;      }      x     =     sum  ;      }      if  (  sum     ==     1     ||     sum     ==     7  )      return     true  ;      return     false  ;   }   // Driver code      var     n     =     13  ;      if     (  isHappynumber  (  n  ))      document  .  write  (  n     +         ' is a Happy number'  );      else      document  .  write  (  n     +         ' is not a Happy number'  );       // This code is contributed by 29AjayKumar     <  /script>   

Išvestis
13 is a Happy number 

Sudėtingumo analizė:

Laiko sudėtingumas: O(n*log(n)).
Pagalbinė erdvė: O(1). 

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