The Artima Developer Community
Sponsored Link

Java Answers Forum
I need to create a numerical palindrome program

5 replies on 1 page. Most recent reply: Jul 26, 2007 5:24 PM by Sunil P

Welcome Guest
  Sign In

Go back to the topic listing  Back to Topic List Click to reply to this topic  Reply to this Topic Click to search messages in this forum  Search Forum Click for a threaded view of the topic  Threaded View   
Previous Topic   Next Topic
Flat View: This topic has 5 replies on 1 page
Dustin

Posts: 1
Nickname: jeeper
Registered: Jun, 2003

I need to create a numerical palindrome program Posted: Jun 15, 2003 8:28 PM
Reply to this message Reply
Advertisement
It needs to take in a number thenif it is a palindrome print out true if it is not it needs to add that number to its self and then check if it is a palindrome if it isn't recheck that and see if it is a palindrome reapet ten time then print out false


ex 155 = false so
155+551
706 = false
706 + 607
1313 + false ten times or until it become a palindrome thanks


E. Nielsen

Posts: 9
Nickname: en
Registered: Feb, 2003

Re: I need to create a numerical palindrome program Posted: Jun 16, 2003 6:01 PM
Reply to this message Reply
Just do it!

.->

Mr Plow

Posts: 18
Nickname: mrplow
Registered: Jun, 2003

Re: I need to create a numerical palindrome program Posted: Jun 16, 2003 7:58 PM
Reply to this message Reply
Not the prettiest code, but it works.


public class Palindrome
{
public static void main(String[] args)
{
//The number to be tested...
int x = 155;

//Loop through a maximum of 10 times
for(int i = 1 ; i <= 10; i++)
{
//check if palindrome, if yes, print out result and break out of loop
if(isPali(x))
{System.out.println(x + " is a palindrome\nIt took " + i + " times through the for loop to get this result."); break;}

//check to make sure that you haven't already looped 10 times.
if(i == 10)
{
System.out.println("After 10 iterations, this number: " + x + " is still not a palindrome... exiting");
break;
}

//reverse the number and add the reversed number to the orginal. Also print out what the program is doing so that the user
//can follow what is happening
StringBuffer sb = new StringBuffer(x + "");
StringBuffer sb2 = sb.reverse();
String s3 = sb2.toString();
int x2 = Integer.parseInt(s3);
System.out.println("x = " + x);
System.out.println("x reversed = " + x2);
x += x2;
System.out.println("x + x reversed = " + x);

}//end of for loop
}//end of main() method


//static method that can be called to see if a given number is a palidrome
public static boolean isPali(int l)
{
String longAsString = l + "";
int x = longAsString.length();

//logic to handle single digit input
if (x == 1)
{
return true;
}

//logic to handle double digit input
if(x == 2)
{
char x1 = longAsString.charAt(0);
char x2 = longAsString.charAt(1);
return x1 == x2;
}


//logic to handle input with odd number of digits
if( (x % 2) == 1)
{
//Remove middle char which doesn't need to match
StringBuffer newString = new StringBuffer();
int xx = x;
int y = (xx / 2);
newString.append(longAsString.substring(0, y));
newString.append(longAsString.substring(y + 1));
String ss = newString.toString();
int xxx = ss.length();
for(int i = 0; i < xxx/2; i++)
{
char xFirst = ss.charAt(i);
char xLast = ss.charAt(xxx - (i + 1));
if(xFirst != xLast)
{
return false;
}
}
return true;
}//end of if odd number of digits.



//logic to handle input with even number of digits
if( (x % 2) == 0)
{
int xx = longAsString.length();
for(int i = 0; i < xx/2; i++)
{
char xFirst = longAsString.charAt(i);
char xLast = longAsString.charAt(xx - (i + 1));
if(xFirst != xLast)
{
return false;
}
}
return true;
}//end of if even number of digits

//default return value
return false;
}
};

Raja Datla

Posts: 1
Nickname: datla
Registered: Jul, 2007

Re: I need to create a numerical palindrome program Posted: Jul 2, 2007 3:42 AM
Reply to this message Reply
for Logic 2 why can't we directly send true .. the palindrome of two numbers is always true. right ?

Sunil P

Posts: 2
Nickname: sunlee79
Registered: Jul, 2007

Re: I need to create a numerical palindrome program Posted: Jul 26, 2007 5:23 PM
Reply to this message Reply
public class Palindrome {


public static void main(String args[]) {

int numberInput = Integer.parseInt(args[0]);
int paliNum = 0;
boolean isNumberPali = false;
System.out.println("input number was : " + numberInput);

for (int j = 0 ; j < 10 ; j++) {

if(isPalindrome(numberInput)) {
isNumberPali = true;
paliNum = numberInput;
break;
}

numberInput += numberInput;
System.out.println("new number is : " + numberInput);

}

if(isNumberPali == true) {
System.out.println(paliNum + " is palindrome!!!");
}
else {
System.out.println("not a palindrome!!!");
}
}

protected static boolean isPalindrome (int x) {

int y = getReverse(x);
if (y == x) {
return true;
}

return false;
}

protected static int getReverse (int x) {

int y = 0;
while (x > 0) {
y = y * 10;
y = y + x%10;
x = x/10;
}

return y;
}
}

Sunil P

Posts: 2
Nickname: sunlee79
Registered: Jul, 2007

Re: I need to create a numerical palindrome program Posted: Jul 26, 2007 5:24 PM
Reply to this message Reply
@Raja,
palindrome of 1 number is always true ... 53 is not a palindrome. i hope I understood what you said!

Flat View: This topic has 5 replies on 1 page
Topic: I need to create a numerical palindrome program Previous Topic   Next Topic Topic: J2EE - Flex end-to-end setup


Sponsored Links



Google
  Web Artima.com   

Copyright © 1996-2014 Artima, Inc. All Rights Reserved. - Privacy Policy - Terms of Use - Advertise with Us