Bir palindrom yapmak için bir dizeden bir karakteri kaldırın

Bir dize verildiğinde, bundan tam olarak bir karakteri çıkardıktan sonra bu dizeyi bir palindrom yapmanın mümkün olup olmadığını kontrol etmemiz gerekir. 

Örnekler:   

Input : str = abcba Output : Yes we can remove character ‘c’ to make string palindrome Input : str = abcbea Output : Yes we can remove character ‘e’ to make string palindrome Input : str = abecbea It is not possible to make this string palindrome just by removing one character  

Uyumsuzluğun konumunu bularak bu sorunu çözebiliriz. Her yinelemeden sonra orta konuma doğru hareket eden her iki uçta iki işaretçi tutarak dizede döngüye başlarız, bu yineleme bir uyumsuzluk bulduğumuzda durur, çünkü yalnızca bir karakteri kaldırmaya izin verilir, burada iki seçeneğimiz var

Uyumsuzluk durumunda ya sol işaretçiyle işaret edilen karakteri kaldırın ya da sağ işaretçiyle işaret edilen karakteri kaldırın.

Her iki durumu da kontrol edeceğiz, unutmayın, her iki taraftan da eşit sayıda adım geçtik, bu ortadaki dize bir karakteri çıkardıktan sonra da bir palindrom olmalıdır, bu nedenle iki alt diziyi biri sol karakteri kaldırarak, diğeri sağ karakteri kaldırarak kontrol ederiz ve bunlardan biri palindrom ise o zaman karşılık gelen karakteri kaldırarak tam dize palindrom yapabiliriz ve eğer her iki alt dizi de palindrom değilse o zaman verilen kısıtlama altında tam diziyi bir palindrom yapmak mümkün değildir. 

Uygulama:

C++
   // C/C++ program to check whether it is possible to make   // string palindrome by removing one character   #include          using     namespace     std  ;   // Utility method to check if substring from low to high is   // palindrome or not.   bool     isPalindrome  (  string  ::  iterator     low       string  ::  iterator     high  )   {      while     (  low      <     high  )      {      if     (  *  low     !=     *  high  )      return     false  ;      low  ++  ;      high  --  ;      }      return     true  ;   }   // This method returns -1 if it is not possible to make string   // a palindrome. It returns -2 if string is already a palindrome.   // Otherwise it returns index of character whose removal can   // make the whole string palindrome.   int     possiblePalinByRemovingOneChar  (  string     str  )   {      // Initialize low and high by both the ends of the string      int     low     =     0       high     =     str  .  length  ()     -     1  ;      // loop until low and high cross each other      while     (  low      <     high  )      {      // If both characters are equal then move both pointer      // towards end      if     (  str  [  low  ]     ==     str  [  high  ])      {      low  ++  ;      high  --  ;      }      else      {      /* If removing str[low] makes the whole string palindrome.    We basically check if substring str[low+1..high] is    palindrome or not. */      if     (  isPalindrome  (  str  .  begin  ()     +     low     +     1       str  .  begin  ()     +     high  ))      return     low  ;      /* If removing str[high] makes the whole string palindrome    We basically check if substring str[low+1..high] is    palindrome or not. */      if     (  isPalindrome  (  str  .  begin  ()     +     low       str  .  begin  ()     +     high     -     1  ))      return     high  ;      return     -1  ;      }      }      // We reach here when complete string will be palindrome      // if complete string is palindrome then return mid character      return     -2  ;   }   // Driver code to test above methods   int     main  ()   {      string     str     =     'abecbea'  ;      int     idx     =     possiblePalinByRemovingOneChar  (  str  );      if     (  idx     ==     -1  )      cout      < <     'Not Possible   n  '  ;      else     if     (  idx     ==     -2  )      cout      < <     'Possible without removing any character'  ;      else      cout      < <     'Possible by removing character'       < <     ' at index '      < <     idx      < <     '  n  '  ;      return     0  ;   }   
Java
   // Java program to check whether    // it is possible to make string    // palindrome by removing one character   import     java.util.*  ;   class   GFG      {      // Utility method to check if       // substring from low to high is      // palindrome or not.      static     boolean     isPalindrome  (  String     str           int     low       int     high  )      {      while     (  low      <     high  )         {      if     (  str  .  charAt  (  low  )     !=     str  .  charAt  (  high  ))      return     false  ;      low  ++  ;      high  --  ;      }      return     true  ;      }      // This method returns -1 if it is       // not possible to make string a palindrome.       // It returns -2 if string is already       // a palindrome. Otherwise it returns       // index of character whose removal can      // make the whole string palindrome.      static     int     possiblePalinByRemovingOneChar  (  String     str  )      {      // Initialize low and right       // by both the ends of the string      int     low     =     0       high     =     str  .  length  ()     -     1  ;      // loop until low and      // high cross each other      while     (  low      <     high  )         {      // If both characters are equal then       // move both pointer towards end      if     (  str  .  charAt  (  low  )     ==     str  .  charAt  (  high  ))         {      low  ++  ;      high  --  ;      }         else      {      /*    * If removing str[low] makes the     * whole string palindrome. We basically     * check if substring str[low+1..high]    * is palindrome or not.    */      if     (  isPalindrome  (  str       low     +     1       high  ))      return     low  ;      /*    * If removing str[high] makes the whole string     * palindrome. We basically check if substring     * str[low+1..high] is palindrome or not.    */      if     (  isPalindrome  (  str       low       high     -     1  ))      return     high  ;      return     -  1  ;      }      }      // We reach here when complete string       // will be palindrome if complete string       // is palindrome then return mid character      return     -  2  ;      }      // Driver Code      public     static     void     main  (  String  []     args  )      {      String     str     =     'abecbea'  ;      int     idx     =     possiblePalinByRemovingOneChar  (  str  );      if     (  idx     ==     -  1  )      System  .  out  .  println  (  'Not Possible'  );      else     if     (  idx     ==     -  2  )      System  .  out  .  println  (  'Possible without '     +         'removing any character'  );      else      System  .  out  .  println  (  'Possible by removing'     +         ' character at index '     +     idx  );      }   }   // This code is contributed by   // sanjeev2552   
Python3
   # Python program to check whether it is possible to make   # string palindrome by removing one character   # Utility method to check if substring from    # low to high is palindrome or not.   def   isPalindrome  (  string  :   str     low  :   int     high  :   int  )   ->   bool  :   while   low    <   high  :   if   string  [  low  ]   !=   string  [  high  ]:   return   False   low   +=   1   high   -=   1   return   True   # This method returns -1 if it    # is not possible to make string   # a palindrome. It returns -2 if    # string is already a palindrome.   # Otherwise it returns index of   # character whose removal can   # make the whole string palindrome.   def   possiblepalinByRemovingOneChar  (  string  :   str  )   ->   int  :   # Initialize low and right by   # both the ends of the string   low   =   0   high   =   len  (  string  )   -   1   # loop until low and high cross each other   while   low    <   high  :   # If both characters are equal then   # move both pointer towards end   if   string  [  low  ]   ==   string  [  high  ]:   low   +=   1   high   -=   1   else  :   # If removing str[low] makes the whole string palindrome.   # We basically check if substring str[low+1..high] is   # palindrome or not.   if   isPalindrome  (  string     low   +   1     high  ):   return   low   # If removing str[high] makes the whole string palindrome   # We basically check if substring str[low+1..high] is   # palindrome or not   if   isPalindrome  (  string     low     high   -   1  ):   return   high   return   -  1   # We reach here when complete string will be palindrome   # if complete string is palindrome then return mid character   return   -  2   # Driver Code   if   __name__   ==   '__main__'  :   string   =   'abecbea'   idx   =   possiblepalinByRemovingOneChar  (  string  )   if   idx   ==   -  1  :   print  (  'Not possible'  )   else   if   idx   ==   -  2  :   print  (  'Possible without removing any character'  )   else  :   print  (  'Possible by removing character at index'     idx  )   # This code is contributed by   # sanjeev2552   
C#
   // C# program to check whether    // it is possible to make string    // palindrome by removing one character   using     System  ;   class     GFG      {      // Utility method to check if       // substring from low to high is      // palindrome or not.      static     bool     isPalindrome  (  string     str       int     low       int     high  )      {      while     (  low      <     high  )         {      if     (  str  [  low  ]     !=     str  [  high  ])      return     false  ;      low  ++  ;      high  --  ;      }      return     true  ;      }      // This method returns -1 if it is       // not possible to make string a palindrome.       // It returns -2 if string is already       // a palindrome. Otherwise it returns       // index of character whose removal can      // make the whole string palindrome.      static     int     possiblePalinByRemovingOneChar  (  string     str  )      {      // Initialize low and right       // by both the ends of the string      int     low     =     0       high     =     str  .  Length     -     1  ;      // loop until low and      // high cross each other      while     (  low      <     high  )         {      // If both characters are equal then       // move both pointer towards end      if     (  str  [  low  ]     ==     str  [  high  ])         {      low  ++  ;      high  --  ;      }         else      {      /*    * If removing str[low] makes the     * whole string palindrome. We basically     * check if substring str[low+1..high]    * is palindrome or not.    */      if     (  isPalindrome  (  str       low     +     1       high  ))      return     low  ;      /*    * If removing str[high] makes the whole string     * palindrome. We basically check if substring     * str[low+1..high] is palindrome or not.    */      if     (  isPalindrome  (  str       low       high     -     1  ))      return     high  ;      return     -  1  ;      }      }      // We reach here when complete string       // will be palindrome if complete string       // is palindrome then return mid character      return     -  2  ;      }      // Driver Code      public     static     void     Main  (  String  []     args  )      {      string     str     =     'abecbea'  ;      int     idx     =     possiblePalinByRemovingOneChar  (  str  );      if     (  idx     ==     -  1  )      Console  .  Write  (  'Not Possible'  );      else     if     (  idx     ==     -  2  )      Console  .  Write  (  'Possible without '     +         'removing any character'  );      else      Console  .  Write  (  'Possible by removing'     +         ' character at index '     +     idx  );      }   }   // This code is contributed by shivanisinghss2110   
JavaScript
    <  script  >   // JavaScript program to check whether    // it is possible to make string    // palindrome by removing one character   // Utility method to check if    // substring from low to high is   // palindrome or not.   function     isPalindrome  (  str       low       high  )      {      while     (  low      <     high  )         {      if     (  str  .  charAt  (  low  )     !=     str  .  charAt  (  high  ))      return     false  ;      low  ++  ;      high  --  ;      }      return     true  ;      }      // This method returns -1 if it is       // not possible to make string a palindrome.       // It returns -2 if string is already       // a palindrome. Otherwise it returns       // index of character whose removal can      // make the whole string palindrome.      function     possiblePalinByRemovingOneChar  (  str  )      {      // Initialize low and right       // by both the ends of the string      var     low     =     0       high     =     str  .  length     -     1  ;      // loop until low and      // high cross each other      while     (  low      <     high  )         {      // If both characters are equal then       // move both pointer towards end      if     (  str  .  charAt  (  low  )     ==     str  .  charAt  (  high  ))         {      low  ++  ;      high  --  ;      }         else      {      /*    * If removing str[low] makes the     * whole string palindrome. We basically     * check if substring str[low+1..high]    * is palindrome or not.    */      if     (  isPalindrome  (  str       low     +     1       high  ))      return     low  ;      /*    * If removing str[high] makes the whole string     * palindrome. We basically check if substring     * str[low+1..high] is palindrome or not.    */      if     (  isPalindrome  (  str       low       high     -     1  ))      return     high  ;      return     -  1  ;      }      }      // We reach here when complete string       // will be palindrome if complete string       // is palindrome then return mid character      return     -  2  ;      }      // Driver Code      var     str     =     'abecbea'  ;      var     idx     =     possiblePalinByRemovingOneChar  (  str  );      if     (  idx     ==     -  1  )      document  .  write  (  'Not Possible'  );      else     if     (  idx     ==     -  2  )      document  .  write  (  'Possible without '     +         'removing any character'  );      else      document  .  write  (  'Possible by removing'     +         ' character at index '     +     idx  );   // this code is contributed by shivanisinghss2110    <  /script>   

Çıkış
Not Possible  

Zaman karmaşıklığı : O(N)
Uzay Karmaşıklığı: O(1)

 

Test Oluştur