Question

Those are  JAVA Programs. Please write them in recursions , it requires the methods have to be recursive(I understood how to write them by using for loop). Please don't use
any syntax beyond chapter of Recursion. I only covered the materials to recursions and the materials before recursion chapter. Appreciated!

#1) Write a recursive method writesquares that accepts an integer n and prints the first n squares with the odd squares in decending order, followed by the even squares in acending order For example writeSquares(8); prints o 49 25914 16 36 64 writeSquares(11); prints o 121 81 49 25 91 4 16 36 64 100 writeSqures(1) prints writeSqures(O) (or any negative number) prints o nothing #2) Write a recursive method isPalindrome that accepts a String and returns true if it reads the same forwards as backwards. o isPalindrome("madam") o isPalindrome("racecar") o isPalindrome("step on no pets") o isPalindrome("able was I ere l saw elba") o isPalindrome("Java") true true true true false

Answer 1

public class RecursiveMethodsUtil {

    public static void writeSqaures(int n) {
        if(n == 1) {
            System.out.print("1 ");
        } else if(n > 1) {
            if(n % 2 == 0) {
                System.out.print((n-1)*(n-1) + " ");
                writeSqaures(n-2);
                System.out.print(n*n + " ");
            } else {
                System.out.print(n*n + " ");
                writeSqaures(n-2);
                System.out.print((n-1)*(n-1) + " ");
            }
        }
    }

    public static boolean isPalindrome(String s) {
        if(s.length() <= 1) {
            return true;
        } else {
            if(s.charAt(0) != s.charAt(s.length()-1)) {
                return false;
            } else {
                return isPalindrome(s.substring(1, s.length()-1));
            }
        }
    }

    public static void main(String[] args) {
        writeSqaures(8);
        System.out.println();
        writeSqaures(11);
        System.out.println();
        writeSqaures(1);
        System.out.println();
        writeSqaures(0);
        System.out.println();

        System.out.println(isPalindrome("madam"));
        System.out.println(isPalindrome("racecar"));
        System.out.println(isPalindrome("step on no pets"));
        System.out.println(isPalindrome("Java"));
    }

}