Tasked by whom?  A teacher assigning homework?

Does the person assigning the task consider a string to be an array?  How  
about other collection types?  Do they mean that you're only prohibited  
from using things that are literally arrays?  Or is any collection of data  
that uses array-like semantics a problem for some reason?

It seems to me that the easiest way is to take the input data, and  
iterative compare pairs of characters from the beginning and ending of the  
string.  If you reach the middle of the string and every character  
matched, then it's a palindrome.  If you find two characters that don't  
match, it's not.

As long as you are allowed to use a string in your processing, the above  
should be simple enough.  Between the String class, a for() loop, and an  
if() that controls the flow for each character comparison, you've got  
everything you need.

Pete

On Tue, 01 Apr 2008 23:16:49 GMT, "Benjamin Rushing"
<benrushing75@verizon.net> wrote, quoted or indirectly quoted someone
who said :

you will use a loop that will chase left to right and compute the
corresponding right to left char.

Draw some on paper, writing down the indexes of the characters.

    class DetectPalindrome {
       public static void main(String[] args) {
           int number = Integer.parseInt(args[0]);
           System.out.print(number + " is ");
           if (number < 0)
               System.out.println("not a palindrome.");
           else
               System.out.println("a palindrome "
                   + " when written in base "
                   + Math.max(number + 1L, 2));
       }
    }

    There are, I suppose, less elegant approaches involving
the % operator, or conversion to String form and comparing
the results of carefully-chosen charAt() methods.  Ho-hum.

  ^^^^^^^^^^^^^^

Guaranteed to be exactly 5 digits?  Use this to your advantage!

  - Logan

On Tue, 01 Apr 2008 23:16:49 GMT, "Benjamin Rushing"
<benrushing75@verizon.net> wrote, quoted or indirectly quoted someone
who said :

Mathematician's algorithm:

generate all possible palindromes.  Put them in an HashSet.

Look up the candidate. If it in is the set it is a Palindrome.

On Apr 1, 7:16 pm, "Benjamin Rushing" <benrushin...@verizon.net>
wrote:

First, calculate the probability that any given 5 digit number COULD
be a palindrome.
Then ignore the input and output yes or no with the same probability
that the input MIGHT be a palindrom.
For very large datasets, this might be sufficient! ;)

seriously... if it's ALWAYS going to be 5 characters then it's very
easy: compare 1st and last character, 2nd and 3rd character. you could
say:
(input[0]==input[4] && input[1]==input[3]) => palindrome
you will have to find some way to split up your input string... If
you're not sure how then check through Java's string library. There's
several ways to do this. ;)

On Tue, 01 Apr 2008 23:16:49 GMT, "Benjamin Rushing"
<benrushing75@verizon.net> wrote, quoted or indirectly quoted someone
who said :

Slacker's solution:

Reading the number as a string is no problem. It is extra work to read
it as an int.

See http://mindprod.com/applet/fileio.html

reverse the string.  Compare.

To reverse the string without using reverse, cheat, and see how
reverse does it by looking at the code in source.zip

But the point is to LEARN java, not create a palindrome detector, so
this is a stupid solution.