java solve palindrome

Recursive problem solving palindrome

If String is just a character or a 0, it is a palindrome

Otherwise the string comparison of the first and last character

If the first and last character different, then it is not a palindrome

Otherwise, strip off the first and last characters, and then compare the rest of the string

 

 1 public class palindrome {
 2     public static void main(String[] args)
 3     {
 4 
 5         System.out.println(isPalindrome("rotor"));
 6 
 7     }
 8 
 9     static String lastCharacter(String str)
10     {
11         return str.substring(str.length()-1,str.length());
12     }
13 
14     static String firstCharacter(String str)
15     {
16         return str.substring(0,1);
17     }
18 
19     static String middleCharacter(String str)
20     {
21         return str.substring(1,str.length()-1);
22     }
23 
24     static String isPalindrome(String str)
25     {
26         if(str.length()==1 || str.length()==0)
27         {
28             return "equal";
29         }
30         else
31         {
32                   if(firstCharacter(str).equals(lastCharacter(str)))
33                   {
34                       return isPalindrome(middleCharacter(str));
35                   }
36         }
37         return "not equal";
38     }
39 
40 }