În Java Cum se verifică dacă Number/String este Palindrom sau nu?

Publicat: 2021-04-13
În Java Cum se verifică dacă Number:String este Palindrom sau nu?

Ce este numărul palindrom?

Un număr palindromic este un număr (cum ar fi 24842) care remains the same atunci când cifrele sale sunt inversate.

Iată câteva alte nume:

  • palindrom numeral
  • palindrom numeric

În acest tutorial vom trece peste pașii despre cum să verificăm dacă Number and String este sau nu Palindrom.

Dacă aveți oricare dintre întrebările de mai jos, vă aflați la locul potrivit:

  • Program Java pentru a verifica dacă un număr este Palindrom
  • Definiția numerelor palindromice
  • Program Java pentru a verifica dacă șirul dat este un palindrom

Pași – Să începem.

  • Scrieți un program CrunchifyFindPalindromeNumber.java
  • Vom crea 3 metode:
    • crunchifyFindPalindromeUsingForLoop()
    • crunchifyFindPalindromUsingWhileLoop()
    • crunchifyFindPalindromeForString()
  • Imprimați rezultatul

CrunchifyFindPalindromeNumber.java

Vom folosi AtomicInteger aici în acest program Java. Este o valoare int care poate fi actualizată atomic. Consultați specificația VarHandle pentru descrieri ale proprietăților acceselor atomice.

Un AtomicInteger este utilizat în aplicații precum contoarele incrementate atomic și nu poate fi folosit ca înlocuitor pentru un Integer. Cu toate acestea, această clasă extinde Number pentru a permite accesul uniform al instrumentelor și utilităților care se ocupă cu clasele bazate pe numere.

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package crunchify . com . java . tutorials ;
 
import java . util . concurrent . atomic . AtomicInteger ;
 
/**
* @author Crunchify.com
* In Java How to Check if Number/String is Palindrome or not?
*/
 
public class CrunchifyFindPalindromeNumber {
 
     public static void main ( String [ ] args ) {
 
         crunchifyFindPalindromeUsingForLoop ( 24642 ) ;
         crunchifyFindPalindromeUsingWhileLoop ( 34567 ) ;
 
         crunchifyFindPalindromeUsingForLoop ( 987656789 ) ;
         crunchifyFindPalindromeUsingWhileLoop ( 555555 ) ;
 
         crunchifyFindPalindromeUsingForLoop ( 1 ) ;
         crunchifyFindPalindromeUsingWhileLoop ( 989 ) ;
 
         crunchifyPrint ( "" ) ;
         crunchifyFindPalindromeForString ( "abcdefedcba" ) ;
         crunchifyFindPalindromeForString ( "abcdefghij" ) ;
     }
 
     // Method 1: Find Palindrome for String
     private static void crunchifyFindPalindromeForString ( String crunchifyString ) {
 
         // reverse(): AbstractStringBuilder Causes this character sequence to be replaced by the reverse of the sequence.
         // If there are any surrogate pairs included in the sequence, these are treated as single characters for the reverse operation.
         // Thus, the order of the high-low surrogates is never reversed. Let n be the character length of this character sequence
         // (not the length in char values) just prior to execution of the reverse method. Then the character at index k in the new character
         // sequence is equal to the character at index n-k-1 in the old character sequence.
         String crunchifyReverse = new StringBuffer ( crunchifyString ) . reverse ( ) . toString ( ) ;
 
         // checks whether the string is palindrome or not
         if ( crunchifyString . equals ( crunchifyReverse ) )
             crunchifyPrint ( crunchifyString + " --> Yes, it is a palindrome String." ) ;
         else
             crunchifyPrint ( crunchifyString + " --> No, it is not a palindrome String." ) ;
     }
 
     // Simple Print Utility
     private static void crunchifyPrint ( String crunchifyString ) {
         System . out . println ( crunchifyString ) ;
     }
 
 
     // Method 2: Find Palindrome for Integer using For Loop
     private static void crunchifyFindPalindromeUsingForLoop ( int number ) {
 
         // AtomicInteger: An int value that may be updated atomically.
         // See the VarHandle specification for descriptions of the properties of atomic accesses.
         // An AtomicInteger is used in applications such as atomically incremented counters, and cannot be used as a replacement for an Integer.
         // However, this class does extend Number to allow uniform access by tools and utilities that deal with numerically-based classes.
         AtomicInteger reverseNumber = new AtomicInteger ( ) ;
         AtomicInteger crunchifyRemainder = new AtomicInteger ( ) ;
         int crunchifyOriginal ;
 
         AtomicInteger crunchifyNumber = new AtomicInteger ( number ) ;
         crunchifyOriginal = crunchifyNumber . get ( ) ;
 
         // reversed integer is stored in variable
 
         // updateAndGet Atomically updates (with memory effects as specified by VarHandle.compareAndSet) the current value with the results of
         // applying the given function, returning the updated value.
         // The function should be side-effect-free, since it may be re-applied when attempted updates fail due to contention among threads.
         for ( ; crunchifyNumber . get ( ) ! = 0 ; crunchifyNumber . updateAndGet ( v - > v / 10 ) ) {
             crunchifyRemainder . set ( crunchifyNumber . get ( ) % 10 ) ;
             reverseNumber . set ( reverseNumber . get ( ) * 10 + crunchifyRemainder . get ( ) ) ;
         }
 
         // Palindrome is a number that remains the same when its digits are reversed.
         if ( crunchifyOriginal == reverseNumber . get ( ) )
             crunchifyPrint ( crunchifyOriginal + " --> Yes, it is a palindrome Number." ) ;
         else
             crunchifyPrint ( crunchifyOriginal + " --> No, it is not a palindrome Number." ) ;
     }
 
     // Method 3: Find Palindrome for Integer using While Loop
     private static void crunchifyFindPalindromeUsingWhileLoop ( int number ) {
         AtomicInteger reverseNumber = new AtomicInteger ( ) ;
         AtomicInteger crunchifyRemainder = new AtomicInteger ( ) ;
         int crunchifyOriginal ;
 
         int crunchifyNumber = number ;
         crunchifyOriginal = crunchifyNumber ;
 
         while ( crunchifyNumber ! = 0 ) {
             crunchifyRemainder . set ( crunchifyNumber % 10 ) ;
 
             // set() Sets the value to newValue, with memory effects as specified by VarHandle.
             // get() Returns the current value, with memory effects as specified by VarHandle.getVolatile.
             reverseNumber . set ( reverseNumber . get ( ) * 10 + crunchifyRemainder . get ( ) ) ;
             crunchifyNumber /= 10 ;
         }
 
         // Palindrome is a number that remains the same when its digits are reversed.
         if ( crunchifyOriginal == reverseNumber . get ( ) )
             crunchifyPrint ( crunchifyOriginal + " --> Yes, is a palindrome Number." ) ;
         else
             crunchifyPrint ( crunchifyOriginal + " --> No, is not a palindrome Number." ) ;
     }
 
}
 

Doar rulați programul de mai sus ca aplicație Java și ar trebui să rezulte ca mai jos.

Rezultatul consolei Eclipse / IntelliJ IDEA.

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24642 -- > Yes , it is a palindrome Number .
34567 -- > No , is not a palindrome Number .
987656789 -- > Yes , it is a palindrome Number .
555555 -- > Yes , is a palindrome Number .
1 -- > Yes , it is a palindrome Number .
989 -- > Yes , is a palindrome Number .
 
abcdefedcba -- > Yes , it is a palindrome String .
abcdefghij -- > No , it is not a palindrome String .
 
Process finished with exit code 0

Anunțați-mă dacă vă confruntați cu vreo problemă la rularea programului de mai sus.