Controleer of rekenkundige progressie kan worden gevormd op basis van de gegeven array

Controleer of rekenkundige progressie kan worden gevormd op basis van de gegeven array
Probeer het eens op GfG Practice

Gegeven een array van N gehele getallen. De taak is om te controleren of een rekenkundige progressie kan worden gevormd met behulp van alle gegeven elementen. Indien mogelijk drukt u 'Ja' af, anders drukt u 'Nee' af.

Voorbeelden:  

Invoer: arr[] = {0 12 4 8}
Uitgang: Ja
Herschik de gegeven array als {0 4 8 12}, wat een rekenkundige progressie vormt.

Invoer: arr[] = {12 40 11 20}
Uitgang: Nee

Sorteren gebruiken - O(n Log n) Tijd

Het idee is om de gegeven array te sorteren. Controleer na het sorteren of de verschillen tussen opeenvolgende elementen hetzelfde zijn of niet. Als alle verschillen hetzelfde zijn, is rekenkundige progressie mogelijk. Raadpleeg alstublieft - Programma om de rekenkundige voortgang te controleren voor de implementatie van deze aanpak.

Telsortering gebruiken - O(n) Tijd en O(n) Ruimte

We kunnen de benodigde ruimte in methode 3 verminderen als de gegeven array kan worden gewijzigd. 

  1. Vind de kleinste en op een na kleinste elementen.
  2. Vind d = tweede_kleinste - kleinste
  3. Trek het kleinste element af van alle elementen.
  4. Als de gegeven array AP vertegenwoordigt, moeten alle elementen de vorm i*d hebben, waarbij i varieert van 0 tot n-1.
  5. Deel alle gereduceerde elementen één voor één met d. Als een element niet deelbaar is door d, retourneer dan false.
  6. Als array AP vertegenwoordigt, moet het een permutatie van getallen van 0 tot n-1 zijn. We kunnen dit eenvoudig controleren met behulp van telsortering.

Hieronder vindt u de implementatie van deze methode:

C++
   // C++ program to check if a given array   // can form arithmetic progression   #include          using     namespace     std  ;   // Checking if array is permutation    // of 0 to n-1 using counting sort   bool     countingsort  (  int     arr  []     int     n  )   {      int     count  [  n  ]     =     {     0     };          // Counting the frequency      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )     {      count  [  arr  [  i  ]]  ++  ;      }          // Check if each frequency is 1 only      for     (  int     i     =     0  ;     i      <=     n  -1  ;     i  ++  )     {      if     (  count  [  i  ]     !=     1  )      return     false  ;      }          return     true  ;   }   // Returns true if a permutation of arr[0..n-1]   // can form arithmetic progression   bool     checkIsAP  (  int     arr  []     int     n  )   {      int     smallest     =     INT_MAX       second_smallest     =     INT_MAX  ;      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )     {          // Find the smallest and       // update second smallest      if     (  arr  [  i  ]      <     smallest  )     {      second_smallest     =     smallest  ;      smallest     =     arr  [  i  ];      }          // Find second smallest      else     if     (  arr  [  i  ]     !=     smallest      &&     arr  [  i  ]      <     second_smallest  )      second_smallest     =     arr  [  i  ];      }      // Find the difference between smallest and second      // smallest      int     diff     =     second_smallest     -     smallest  ;      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )     {      arr  [  i  ]  =  arr  [  i  ]  -  smallest  ;      }          for  (  int     i  =  0  ;  i   <  n  ;  i  ++  )      {      if  (  arr  [  i  ]  %  diff  !=  0  )      {      return     false  ;      }      else      {      arr  [  i  ]  =  arr  [  i  ]  /  diff  ;      }      }          // If array represents AP it must be a       // permutation of numbers from 0 to n-1.      // Check this using counting sort.      if  (  countingsort  (  arr    n  ))      return     true  ;      else      return     false  ;   }   // Driven Program   int     main  ()   {      int     arr  []     =     {     20       15       5       0       10     };      int     n     =     sizeof  (  arr  )     /     sizeof  (  arr  [  0  ]);      (  checkIsAP  (  arr       n  ))     ?     (  cout      < <     'Yes'      < <     endl  )      :     (  cout      < <     'No'      < <     endl  );      return     0  ;      // This code is contributed by Pushpesh Raj   }   
Java
   // Java program to check if a given array   // can form arithmetic progression   import     java.io.*  ;   class   GFG     {      // Checking if array is permutation      // of 0 to n-1 using counting sort      static     boolean     countingsort  (  int     arr  []       int     n  )      {      int  []     count     =     new     int  [  n  ]  ;      for  (  int     i     =     0  ;     i      <     n  ;     i  ++  )      count  [  i  ]     =     0  ;      // Counting the frequency      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )     {      count  [  arr  [  i  ]]++  ;      }      // Check if each frequency is 1 only      for     (  int     i     =     0  ;     i      <=     n  -  1  ;     i  ++  )     {      if     (  count  [  i  ]     !=     1  )      return     false  ;      }      return     true  ;      }      // Returns true if a permutation of arr[0..n-1]      // can form arithmetic progression      static     boolean     checkIsAP  (  int     arr  []       int     n  )      {      int     smallest     =     Integer  .  MAX_VALUE       second_smallest     =     Integer  .  MAX_VALUE     ;      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )     {      // Find the smallest and      // update second smallest      if     (  arr  [  i  ]      <     smallest  )     {      second_smallest     =     smallest  ;      smallest     =     arr  [  i  ]  ;      }      // Find second smallest      else     if     (  arr  [  i  ]     !=     smallest      &&     arr  [  i  ]      <     second_smallest  )      second_smallest     =     arr  [  i  ]  ;      }      // Find the difference between smallest and second      // smallest      int     diff     =     second_smallest     -     smallest  ;      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )     {      arr  [  i  ]     =     arr  [  i  ]     -     smallest  ;      }      for  (  int     i     =     0  ;     i      <     n  ;     i  ++  )      {      if  (  arr  [  i  ]     %     diff     !=     0  )      {      return     false  ;      }      else      {      arr  [  i  ]     =     arr  [  i  ]/  diff  ;      }      }      // If array represents AP it must be a      // permutation of numbers from 0 to n-1.      // Check this using counting sort.      if  (  countingsort  (  arr    n  ))      return     true  ;      else      return     false  ;      }      // Driven Program      public     static     void     main     (  String  []     args  )      {      int     arr  []     =     {     20       15       5       0       10     };      int     n     =     arr  .  length  ;      if  (  checkIsAP  (  arr       n  ))         System  .  out  .  println  (  'Yes'  );      else     System  .  out  .  println  (  'No'  );      }   }   // This code is contributed by Utkarsh   
Python
   # Python program to check if a given array   # can form arithmetic progression   import   sys   # Checking if array is permutation    # of 0 to n-1 using counting sort   def   countingsort  (   arr     n  ):   count   =   [  0  ]  *  n  ;   # Counting the frequency   for   i   in   range  (  0     n  ):   count  [  arr  [  i  ]]   +=   1  ;   # Check if each frequency is 1 only   for   i   in   range  (  0     n   -   1  ):   if   (  count  [  i  ]   !=   1  ):   return   False  ;   return   True  ;   # Returns true if a permutation of arr[0..n-1]   # can form arithmetic progression   def   checkIsAP  (   arr     n  ):   smallest   =   sys  .  maxsize  ;   second_smallest   =   sys  .  maxsize  ;   for   i   in   range  (  0    n  ):   # Find the smallest and    # update second smallest   if   (  arr  [  i  ]    <   smallest  )   :   second_smallest   =   smallest  ;   smallest   =   arr  [  i  ];   # Find second smallest   elif   (  arr  [  i  ]   !=   smallest   and   arr  [  i  ]    <   second_smallest  ):   second_smallest   =   arr  [  i  ];   # Find the difference between smallest and second   # smallest   diff   =   second_smallest   -   smallest  ;   for   i   in   range  (  0    n  ):   arr  [  i  ]  =  arr  [  i  ]  -  smallest  ;   for   i   in   range  (  0    n  ):   if  (  arr  [  i  ]  %  diff  !=  0  ):   return   False  ;   else  :   arr  [  i  ]  =  (  int  )(  arr  [  i  ]  /  diff  );   # If array represents AP it must be a    # permutation of numbers from 0 to n-1.   # Check this using counting sort.   if  (  countingsort  (  arr    n  )):   return   True  ;   else  :   return   False  ;   # Driven Program   arr   =   [   20     15     5     0     10   ];   n   =   len  (  arr  );   if  (  checkIsAP  (  arr     n  )):   print  (  'Yes'  );   else  :   print  (  'NO'  );   # This code is contributed by ratiagrawal.   
C#
   using     System  ;      class     GFG      {      // Checking if array is permutation      // of 0 to n-1 using counting sort      static     bool     CountingSort  (  int  []     arr       int     n  )      {      // Counting the frequency      int  []     count     =     new     int  [  n  ];      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )      {      count  [  arr  [  i  ]]  ++  ;      }      // Check if each frequency is 1 only      for     (  int     i     =     0  ;     i      <=     n     -     1  ;     i  ++  )      {      if     (  count  [  i  ]     !=     1  )      {      return     false  ;      }      }      return     true  ;      }  // Returns true if a permutation of arr[0..n-1]      // can form arithmetic progression      static     bool     CheckIsAP  (  int  []     arr       int     n  )      {  // Find the smallest and      // update second smallest      int     smallest     =     int  .  MaxValue  ;      int     secondSmallest     =     int  .  MaxValue  ;      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )      {      if     (  arr  [  i  ]      <     smallest  )      {      secondSmallest     =     smallest  ;      smallest     =     arr  [  i  ];      }      else     if     (  arr  [  i  ]     !=     smallest     &&     arr  [  i  ]      <     secondSmallest  )      {      secondSmallest     =     arr  [  i  ];      }      }      int     diff     =     secondSmallest     -     smallest  ;      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )      {      arr  [  i  ]     =     arr  [  i  ]     -     smallest  ;      }      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )      {      if     (  arr  [  i  ]     %     diff     !=     0  )      {      return     false  ;      }      else      {      arr  [  i  ]     =     arr  [  i  ]     /     diff  ;      }      }   // If array represents AP it must be a      // permutation of numbers from 0 to n-1.      // Check this using counting sort.      if     (  CountingSort  (  arr       n  ))      {      return     true  ;      }      else      {      return     false  ;      }      }   // Driven Program      static     void     Main  (  string  []     args  )      {      int  []     arr     =     new     int  []     {     20       15       5       0       10     };      int     n     =     arr  .  Length  ;      Console  .  WriteLine  (  CheckIsAP  (  arr       n  )     ?     'Yes'     :     'No'  );      }      }   
JavaScript
   // Javascript program to check if a given array   // can form arithmetic progression   // Checking if array is permutation    // of 0 to n-1 using counting sort   function     countingsort  (     arr       n  )   {      let     count  =  new     Array  (  n  ).  fill  (  0  );          // Counting the frequency      for     (  let     i     =     0  ;     i      <     n  ;     i  ++  )     {      count  [  arr  [  i  ]]  ++  ;      }          // Check if each frequency is 1 only      for     (  let     i     =     0  ;     i      <=     n  -  1  ;     i  ++  )     {      if     (  count  [  i  ]     !=     1  )      return     false  ;      }          return     true  ;   }   // Returns true if a permutation of arr[0..n-1]   // can form arithmetic progression   function     checkIsAP  (     arr       n  )   {      let     smallest     =     Number  .  MAX_SAFE_INTEGER       second_smallest     =     Number  .  MAX_SAFE_INTEGER  ;      for     (  let     i     =     0  ;     i      <     n  ;     i  ++  )     {          // Find the smallest and       // update second smallest      if     (  arr  [  i  ]      <     smallest  )     {      second_smallest     =     smallest  ;      smallest     =     arr  [  i  ];      }          // Find second smallest      else     if     (  arr  [  i  ]     !=     smallest      &&     arr  [  i  ]      <     second_smallest  )      second_smallest     =     arr  [  i  ];      }      // Find the difference between smallest and second      // smallest      let     diff     =     second_smallest     -     smallest  ;      for     (  let     i     =     0  ;     i      <     n  ;     i  ++  )     {      arr  [  i  ]  =  arr  [  i  ]  -  smallest  ;      }          for  (  let     i  =  0  ;  i   <  n  ;  i  ++  )      {      if  (  arr  [  i  ]  %  diff  !=  0  )      {      return     false  ;      }      else      {      arr  [  i  ]  =  arr  [  i  ]  /  diff  ;      }      }          // If array represents AP it must be a       // permutation of numbers from 0 to n-1.      // Check this using counting sort.      if  (  countingsort  (  arr    n  ))      return     true  ;      else      return     false  ;   }   // Driven Program   let     arr     =     [  20       15       5       0       10     ];   let     n     =     arr  .  length  ;   (  checkIsAP  (  arr       n  ))     ?     (  console  .  log  (  'Yesn'  ))      :     (  console  .  log  (  'Non'  ));          // // This code was contributed by poojaagrawal2.   

Uitvoer
Yes 

Tijdcomplexiteit - O(n) 
Hulpruimte - O(n)

Hashing met Single Pass - O(n) tijd en O(n) ruimte

Het basisidee is om het gemeenschappelijke verschil van de AP te vinden door het maximale en het minimale element van de array te achterhalen. Begin daarna vanaf de maximale waarde en blijf de waarde verlagen met het gemeenschappelijke verschil, terwijl u controleert of deze nieuwe waarde aanwezig is in de hashmap of niet. Als de waarde op enig moment niet aanwezig is in de hashset, verbreek dan de lus. De ideale situatie na het verbreken van de lus is dat alle n elementen zijn afgedekt en als dat zo is, retourneert u waar, anders retourneert u onwaar. 

C++
   // C++ program for above approach   #include          using     namespace     std  ;   bool     checkIsAP  (  int     arr  []     int     n  )   {      unordered_set   <  int  >     st  ;      int     maxi     =     INT_MIN  ;      int     mini     =     INT_MAX  ;      for     (  int     i  =  0  ;  i   <  n  ;  i  ++  )     {      maxi     =     max  (  arr  [  i  ]     maxi  );      mini     =     min  (  arr  [  i  ]     mini  );      st  .  insert  (  arr  [  i  ]);      }          // FINDING THE COMMON DIFFERENCE      int     diff     =     (  maxi     -     mini  )     /     (  n     -     1  );      int     count     =     0  ;      // CHECK TERMS OF AP PRESENT IN THE HASHSET      while     (  st  .  find  (  maxi  )  !=  st  .  end  ())     {      count  ++  ;      maxi     =     maxi     -     diff  ;      }          if     (  count     ==     n  )      return     true  ;      return     false  ;   }   // Driver Code   int     main  ()   {      int     arr  []     =     {     0       12       4       8     };      int     n     =     4  ;      cout      < <     boolalpha      < <     checkIsAP  (  arr       n  );      return     0  ;   }   // This code is contributed by Rohit Pradhan   
Java
   /*package whatever //do not write package name here */   import     java.io.*  ;   import     java.util.*  ;   class   GFG     {      public     static     void     main  (  String  []     args  )      {      int  []     arr     =     {     0       12       4       8     };      int     n     =     arr  .  length  ;      System  .  out  .  println  (  checkIsAP  (  arr       n  ));      }      static     boolean     checkIsAP  (  int     arr  []       int     n  )      {      HashSet   <  Integer  >     set     =     new     HashSet   <  Integer  >  ();      int     max     =     Integer  .  MIN_VALUE  ;      int     min     =     Integer  .  MAX_VALUE  ;      for     (  int     i     :     arr  )     {      max     =     Math  .  max  (  i       max  );      min     =     Math  .  min  (  i       min  );      set  .  add  (  i  );      }          // FINDING THE COMMON DIFFERENCE      int     diff     =     (  max     -     min  )     /     (  n     -     1  );      int     count     =     0  ;      // CHECK IF TERMS OF AP PRESENT IN THE HASHSET       while     (  set  .  contains  (  max  ))     {      count  ++  ;      max     =     max     -     diff  ;      }      if     (  count     ==     arr  .  length  )      return     true  ;      return     false  ;      }   }   
Python
   import   sys   def   checkIsAP  (  arr     n  ):   Set   =   set  ()   Max   =   -  sys  .  maxsize   -   1   Min   =   sys  .  maxsize   for   i   in   arr  :   Max   =   max  (  i     Max  )   Min   =   min  (  i     Min  )   Set  .  add  (  i  )   # FINDING THE COMMON DIFFERENCE   diff   =   (  Max   -   Min  )   //   (  n   -   1  )   count   =   0   # CHECK IF TERMS OF AP PRESENT IN THE HASHSET    while   (  Max   in   Set  ):   count   +=   1   Max   =   Max   -   diff   if   (  count   ==   len  (  arr  )):   return   True   return   False   # driver code   arr   =   [   0     12     4     8   ]   n   =   len  (  arr  )   print  (  checkIsAP  (  arr     n  ))   # This code is contributed by shinjanpatra   
C#
   using     System  ;   using     System.Collections.Generic  ;   public     class     GFG      {      // C# program for above approach      static     bool     checkIsAP  (  int  []     arr       int     n  )      {      HashSet   <  int  >     st     =     new     HashSet   <  int  >  ();      int     maxi     =     int  .  MinValue  ;      int     mini     =     int  .  MaxValue  ;      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )     {      maxi     =     Math  .  Max  (  arr  [  i  ]     maxi  );      mini     =     Math  .  Min  (  arr  [  i  ]     mini  );      st  .  Add  (  arr  [  i  ]);      }          // FINDING THE COMMON DIFFERENCE      int     diff     =     (  maxi     -     mini  )     /     (  n     -     1  );      int     count     =     0  ;      // CHECK IF TERMS OF AP PRESENT IN THE HASHSET       while     (  st  .  Contains  (  maxi  ))     {      count  ++  ;      maxi     =     maxi     -     diff  ;      }      if     (  count     ==     n  )     {      return     true  ;      }      return     false  ;      }      // Driver Code      internal     static     void     Main  ()      {      int  []     arr     =     {     0       12       4       8     };      int     n     =     4  ;      Console  .  Write  (  checkIsAP  (  arr       n  ));      }      // This code is contributed by Aarti_Rathi   }   
JavaScript
   function     checkIsAP  (  arr       n  ){      set     =     new     Set  ()      let     Max     =     Number  .  MIN_VALUE      let     Min     =     Number  .  MAX_VALUE      for  (  let     i     of     arr  ){      Max     =     Math  .  max  (  i       Max  )      Min     =     Math  .  min  (  i       Min  )      set  .  add  (  i  )      }          // FINDING THE COMMON DIFFERENCE      let     diff     =     Math  .  floor  ((  Max     -     Min  )     /     (  n     -     1  ))      let     count     =     0      // CHECK IF TERMS OF AP PRESENT IN THE HASHSET       while     (  set  .  has  (  Max  )){      count     +=     1      Max     =     Max     -     diff      }      if     (  count     ==     arr  .  length  )      return     true      return     false   }   // driver code   let     arr     =     [     0       12       4       8     ]   let     n     =     arr  .  length   console  .  log  (  checkIsAP  (  arr       n  ))   

Uitvoer
true 
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