package homework4;


public class Homework4 {


    
    public static void arrange(int [] arr) {
        // rearrange arr so that evens occur before odds
        recArrange(arr, 0, arr.length-1);
    }
    
    private static void recArrange(int [] arr, int left, int right) {
        // rearrange the portion of arr between left and right
        
        if (right <= left ) return; //base case
        
        if ( (arr[left] % 2) == 0) {
            //arr[left] is even
            recArrange(); //fill in the arguments for recursive call
            return;
        }
        
        int temp = left;
        
        while((temp <= right) && ((arr[temp]%2) != 0))
            temp++; // find first even number
        
        if (temp > right) {
            //no even number found
            return;
        }
        
        // now swap arr[temp] and arr[left]
        int leftStore = arr[left];
        arr[left] = arr[temp];
        arr[temp] = leftStore;
        
        recArrange(); // fill in the recursive call arguments
    }
    
    
    public static boolean isPalindrome(String s) {
        return isPalindrome(s, 0, s.length() - 1); // call recursive method
    } 
    
    private static boolean isPalindrome(String s, int left, int right) {
        //check if s[left..right] is palindrome;
        
       
        //Part of Homework: supply a base case here
        

        // non-base case follows:
        if (s.charAt(left) == s.charAt(right)) {
            return isPalindrome(); // fill in recursive call arguments
        }
        
        return false; //s[left] and s[right] are not equal
    }
    

    public static int oddOneOut(int [] A) { 
	//stub for Part D of homework


    }

    public static void main(String[] args) {
        

        // some test code; can modify this part
        
        int [] A = {10, 13, 11, 12, 17};
        arrange(A);
        for (int i = 0; i < A.length; i++)
            System.out.println(A[i]);
        
        System.out.println(isPalindrome("racecar"));
        System.out.println(isPalindrome("hannah"));
        System.out.println(isPalindrome("abdaba"));
    }
}