finding half palindrome words

[justin marshall]

Hi all, I'm a newbie.
I managed to get a code that checks for palindrome words or strings.
A palindrome is a word that reads the same forwards and backwards. Like "redevider".
Now...How do I check for a HALF palindrome word or string? for example, "redivadar" is half palindrome because 3 out of 5 characters match. "redivaaar" is not even half palindrome because only 2 out of 5 chars match.
below is the code that checks for FULL palindromes.
Any ideas on how to tweak the code to check for HALF palindromes?

public class Palindrome
{
public static void main (String[ ] args)
{
String inputSentence;
int leftCharInputSentence, rightCharInputSentence;
System.out.print("Enter a sentence or word: ");
inputSentence = <custom made method to get input from keyboard>;

rightCharInputSentence = inputSentence.length() - 1;
leftCharInputSentence = 0;

while (inputSentence.charAt(leftCharInputSentence) == inputSentence.charAt(rightCharInputSentence) && leftCharInputSentence < rightCharInputSentence)
{
leftCharInputSentence++;
rightCharInputSentence--;
}
System.out.println();
if (leftCharInputSentence < rightCharInputSentence)
System.out.println (inputSentence + " is NOT a palindrome.");
else
System.out.println (inputSentence + " is a palindrome.");
System.out.println();

}
}

[Jason Menard]

I'm going to move this to Programming Diversions.

[Vinod Chandana]

Hi El,
Try this
/*
* Palindrome.java
*
* Created on October 8, 2003, 2:27 PM
*/
/**
*
* @author Vinod K. Chandana
*/
public class Palindrome
{
public static void main (String[ ] args)
{
String inputSentence;
inputSentence = "redivadar";
int matches = 0;
int length = inputSentence.length() - 1;
int mid = (length + 1)/2;
for(int i = 0; i < mid; i++){
if(inputSentence.charAt(i) == inputSentence.charAt(length - i))
matches++;
}
if(matches < (mid/2))
System.out.println (inputSentence + " is NOT a palindrome.");
else if(matches == mid)
System.out.println (inputSentence + " is a palindrome.");
else if(matches == (mid/2))
System.out.println (inputSentence + " is a half palindrome.");
}
}
Regards,
Vinod

Originally posted by el chupacabra:
Hi all, I'm a newbie.
I managed to get a code that checks for palindrome words or strings.
A palindrome is a word that reads the same forwards and backwards. Like "redevider".
Now...How do I check for a HALF palindrome word or string? for example, "redivadar" is half palindrome because 3 out of 5 characters match. "redivaaar" is not even half palindrome because only 2 out of 5 chars match.
below is the code that checks for FULL palindromes.
Any ideas on how to tweak the code to check for HALF palindromes?

public class Palindrome
{
public static void main (String[ ] args)
{
String inputSentence;
int leftCharInputSentence, rightCharInputSentence;
System.out.print("Enter a sentence or word: ");
inputSentence = <custom made method to get input from keyboard>;

rightCharInputSentence = inputSentence.length() - 1;
leftCharInputSentence = 0;

while (inputSentence.charAt(leftCharInputSentence) == inputSentence.charAt(rightCharInputSentence) && leftCharInputSentence < rightCharInputSentence)
{
leftCharInputSentence++;
rightCharInputSentence--;
}
System.out.println();
if (leftCharInputSentence < rightCharInputSentence)
System.out.println (inputSentence + " is NOT a palindrome.");
else
System.out.println (inputSentence + " is a palindrome.");
System.out.println();

}
}

[justin marshall]

thank you thank you thank you.
I got the concept and the sample code is great!!
el chupacabra.

[Michael Matola]

Great nickname, El Chupacabra!
But please adjust your displayed name to meet the JavaRanch Naming Policy. You can do so here.
Have fun on the 'Ranch. (We got some cattle and moose round these parts, but not too many goats.)

[Stan James]

Just curious, does that algorithm work equally well for palindromes with even number letters an odd number letters? BOB and BOOB? Would left>=right instead of left>right end differently?