/*
 * 判断一个字符串是否是回文；
 */
public class Palindrome {
	public static boolean isPalindrome(String s,int i,int j){
		if(i > j)
			throw new IllegalArgumentException();
		if(i == j)
			return true;
		else{
			return (s.charAt(i) == s.charAt(j)) && isPalindrome(s,i+1,j-1);
		}
	}
	
	public static void main(String[] args){
		String test = "ABCBA";
		int i = 0;
		int j = test.length() - 1;
		System.out.println(test + " is Palindrome? " + Palindrome.isPalindrome(test, i, j));
	}
}