Plassering av et element etter stabil sortering

Plassering av et element etter stabil sortering
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Gitt en rekke heltall som kan inneholde dupliserte elementer et element i denne matrisen er gitt til oss, må vi fortelle den endelige posisjonen til dette elementet i matrisen hvis en stabil sorteringsalgoritme brukes.

Eksempler:  

Input : arr[] = [3 4 3 5 2 3 4 3 1 5] index = 5 Output : 4 Element initial index – 5 (third 3) After sorting array by stable sorting algorithm we get array as shown below [1(8) 2(4) 3(0) 3(2) 3(5) 3(7) 4(1) 4(6) 5(3) 5(9)] with their initial indices shown in parentheses next to them Element's index after sorting = 4 
Recommended Practice Stabil sortering og plassering Prøv det!

En enkel måte å løse dette problemet på er å bruke en hvilken som helst stabil sorteringsalgoritme som Innsettingssortering Sort går etc og få den nye indeksen for gitt element, men vi kan løse dette problemet uten å sortere matrisen. 

Posisjonen til et element i en sortert matrise bestemmes kun av de elementene som er mindre enn gitt element. Vi teller alle matriseelementer som er mindre enn gitt element, og for de elementene som er lik gitte elementelementer som forekommer før gitte elementers indeks vil bli inkludert i antallet av mindre elementer, vil dette sikre stabiliteten til resultatets indeks. 

Enkel kode for å implementere tilnærmingen ovenfor er implementert nedenfor: 

C++
   // C++ program to get index of array element in    // sorted array    #include             using     namespace     std  ;      // Method returns the position of arr[idx] after    // performing stable-sort on array    int     getIndexInSortedArray  (  int     arr  []     int     n       int     idx  )      {         /* Count of elements smaller than current     element plus the equal element occurring     before given index*/      int     result     =     0  ;         for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )     {         // If element is smaller then increase       // the smaller count       if     (  arr  [  i  ]      <     arr  [  idx  ])         result  ++  ;         // If element is equal then increase count       // only if it occurs before       if     (  arr  [  i  ]     ==     arr  [  idx  ]     &&     i      <     idx  )         result  ++  ;         }         return     result  ;      }      // Driver code to test above methods    int     main  ()      {         int     arr  []     =     {     3       4       3       5       2       3       4       3       1       5     };         int     n     =     sizeof  (  arr  )     /     sizeof  (  arr  [  0  ]);         int     idxOfEle     =     5  ;         cout      < <     getIndexInSortedArray  (  arr       n       idxOfEle  );         return     0  ;      }      
Java
   // Java program to get index of array   // element in sorted array   class   ArrayIndex     {      // Method returns the position of      // arr[idx] after performing stable-sort      // on array      static     int     getIndexInSortedArray  (  int     arr  []        int     n       int     idx  )      {      /* Count of elements smaller than     current element plus the equal element    occurring before given index*/      int     result     =     0  ;      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )     {      // If element is smaller then      // increase the smaller count      if     (  arr  [  i  ]      <     arr  [  idx  ]  )      result  ++  ;      // If element is equal then increase      // count only if it occurs before      if     (  arr  [  i  ]     ==     arr  [  idx  ]     &&     i      <     idx  )      result  ++  ;      }      return     result  ;      }      // Driver code to test above methods      public     static     void     main  (  String  []     args  )      {      int     arr  []     =     {     3       4       3       5       2       3       4       3       1       5     };      int     n     =     arr  .  length  ;      int     idxOfEle     =     5  ;      System  .  out  .  println  (  getIndexInSortedArray  (  arr        n       idxOfEle  ));      }   }   // This code is contributed by Raghav sharma   
Python3
   # Python program to get index of array element in   # sorted array   # Method returns the position of arr[idx] after   # performing stable-sort on array   def   getIndexInSortedArray  (  arr     n     idx  ):   # Count of elements smaller than current   # element plus the equal element occurring   # before given index   result   =   0   for   i   in   range  (  n  ):   # If element is smaller then increase   # the smaller count   if   (  arr  [  i  ]    <   arr  [  idx  ]):   result   +=   1   # If element is equal then increase count   # only if it occurs before   if   (  arr  [  i  ]   ==   arr  [  idx  ]   and   i    <   idx  ):   result   +=   1   return   result  ;   # Driver code to test above methods   arr   =   [  3     4     3     5     2     3     4     3     1     5  ]   n   =   len  (  arr  )   idxOfEle   =   5   print   (  getIndexInSortedArray  (  arr     n     idxOfEle  ))   # Contributed by: Afzal Ansari   
C#
   // C# program to get index of array   // element in sorted array   using     System  ;   class     ArrayIndex     {          // Method returns the position of      // arr[idx] after performing stable-sort      // on array      static     int     getIndexInSortedArray  (  int  []     arr        int     n       int     idx  )      {      /* Count of elements smaller than     current element plus the equal element    occurring before given index*/      int     result     =     0  ;      for     (  int     i     =     0  ;     i      <     n  ;     i  ++  )     {          // If element is smaller then      // increase the smaller count      if     (  arr  [  i  ]      <     arr  [  idx  ])      result  ++  ;      // If element is equal then increase      // count only if it occurs before      if     (  arr  [  i  ]     ==     arr  [  idx  ]     &&     i      <     idx  )      result  ++  ;      }      return     result  ;      }      // Driver code to test above methods      public     static     void     Main  ()      {      int  []     arr     =     {     3       4       3       5       2       3       4       3       1       5     };      int     n     =     arr  .  Length  ;      int     idxOfEle     =     5  ;      Console  .  WriteLine  (  getIndexInSortedArray  (  arr       n           idxOfEle  ));      }   }   // This code is contributed by vt_m   
PHP
      // PHP program to get index of   // array element in sorted array   // Method returns the position of    // arr[idx] after performing    // stable-sort on array   function   getIndexInSortedArray  (   $arr     $n     $idx  )   {   /* Count of elements smaller    than current element plus     the equal element occurring    before given index */   $result   =   0  ;   for  (  $i   =   0  ;   $i    <   $n  ;   $i  ++  )   {   // If element is smaller then   // increase the smaller count   if   (  $arr  [  $i  ]    <   $arr  [  $idx  ])   $result  ++  ;   // If element is equal then   // increase count only if    // it occurs before   if   (  $arr  [  $i  ]   ==   $arr  [  $idx  ]   and   $i    <   $idx  )   $result  ++  ;   }   return   $result  ;   }   // Driver Code   $arr   =   array  (  3     4     3     5     2     3     4     3     1     5  );   $n   =  count  (  $arr  );   $idxOfEle   =   5  ;   echo   getIndexInSortedArray  (  $arr     $n     $idxOfEle  );   // This code is contributed by anuj_67.   ?>   
JavaScript
    <  script  >   // JavaScript program to get index of array   // element in sorted array      // Method returns the position of      // arr[idx] after performing stable-sort      // on array      function     getIndexInSortedArray  (  arr        n       idx  )      {      /* Count of elements smaller than     current element plus the equal element    occurring before given index*/      let     result     =     0  ;      for     (  let     i     =     0  ;     i      <     n  ;     i  ++  )     {          // If element is smaller then      // increase the smaller count      if     (  arr  [  i  ]      <     arr  [  idx  ])      result  ++  ;          // If element is equal then increase      // count only if it occurs before      if     (  arr  [  i  ]     ==     arr  [  idx  ]     &&     i      <     idx  )      result  ++  ;      }      return     result  ;      }   // Driver Code      let     arr     =     [     3       4       3       5       2       3       4       3       1       5     ];      let     n     =     arr  .  length  ;          let     idxOfEle     =     5  ;      document  .  write  (  getIndexInSortedArray  (  arr        n       idxOfEle  ));       // This code is contributed by code_hunt.     <  /script>   

Produksjon
4 

Tidskompleksitet: På) hvor n er størrelsen på matrisen.
Hjelpeområde: O(1)

 

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