ASM Words

; =========================================================
; Subroutine to check for a palindrome
;
; d0.w = length of string minus 1
; a0.l = starting RAM address of string (must be 8 bits per character)
; returns with ZERO flag set if the string is a palindrome, clear otherwise
; =========================================================
 
CheckPalin:
	andi.l	#$0000FFFF,d0		;allow using d0 as long
	tst.w	d0			;is string 1 character long?
	beq.b	CheckPalin_Return	;if so, return with ZERO flag set
	movea.l	a0,a1
	adda.l	d0,a1			;set a1 to address of last character
	subi.w	#1,d0			;get whole length
	lsr.w	#1,d0			;get half the length
 
CheckPalin_Loop:
	move.b	(a0),d1			;get character from start of string
	cmp.b	(a1),d1			;compare with character from end of string
	bne.b	CheckPalin_Return	;if unequal, return with ZERO flag unset
	adda.l	#1,a0			;increase offset from start of string
	suba.l	#1,a1			;decrease offset from end of string
	dbf	d0,CheckPalin_Loop
	move.w	#0,d0			;set ZERO flag
 
CheckPalin_Return:
	rts

import java.util.Scanner;
 
public class Palindrome
{
	private static Scanner	stdin	= new Scanner( System.in );
	private static String	word	= "";
 
	public static void main( String[] args )
	{
		instructions( );
		while( question( "Enter a string" ) == true )
		{
			if( checkPalindrome( ) )
				System.out.println( "This is a palindrome" );
			else
				System.out.println( "This is not a palindrome" );
		}
	}
 
	private static void instructions( )
	{
		System.out.println( "This program will analize any word to see if" );
		System.out.println( "it is a palindrome or not." );
		System.out.println( "To quit the program, type in 'quit'." );		
	}
 
	private static boolean question( String question )
	{
		System.out.println( question );
		word = stdin.nextLine( );
		if( word.toLowerCase( ).equals( "quit" ) )
			return false;
		else
			return true;
	}
 
	private static boolean checkPalindrome( )
	{
		String reverse = reverseWord( );
		if( word.toLowerCase( ).contentEquals( reverse.toLowerCase( ) ) )
			return true;
		else
			return false;
	}
 
	private static String reverseWord( )
	{
		String newWord = "";
		LinkedStack<Character> wordStack = new LinkedStack<Character>( );
 
		for( int i = 0; i < word.length( ); i++ )
			wordStack.push( word.charAt( i ) );
 
		int size = wordStack.size( );
 
		for( int i = 0; i < size; i++ )
			newWord += wordStack.pop( );
 
		return newWord;
	}
}