public class RecursiveMethods {

    //
    // factorial(n)
    //
    // This is a recursive implementation
    // to find the factorial of an integer n.
    //
    // Note the base case is implied by
    // the assignment of the return variable.
    //
    public static int factorial( int n ) {
	int fact = 1;

	if ( n >= 2 )
	    fact = n * factorial(n-1);

	return( fact );
    }

    //
    // countN() A recursive method to count the number
    // of times the integer n appears in the array.
    //
    // Note that the method is initially passed the length
    // of the array-1 as the sarting index and uses that
    // parameter to determine if the recursion should continue.
    //
    //
    public static int countN( int[] arr, int index, int n ) {
	int count = 0;

        if ( arr != null && index >= 0 ) {
    	    if ( arr[index] == n )
                count = countN( arr, index-1, n ) + 1;
	    else
		count = countN( arr, index-1, n );
	}

	return( count );
    }

    //
    // findMin()
    //
    // This method uses recursion to find the minimum
    // value in an array.
    //
    // note that the explicit base case is handled inside
    // the conditional statement.
    //
    public static int findMin( int[] arr, int index ) {
   	int min = -1;

	if ( arr != null && index >= 0 ) {
	    // The explicit base case is when we hae recursed
	    // back to the first element in the array.
	    if (index == 0)
	        min = arr[0];
	    else
		// The recursive case returns the minimum of
		// the element at the current index and the
		// element returned from the recursive call.
		//
		min = Math.min(arr[index], findMin(arr, index-1));
	}

	return( min );
    }

    public static void main( String s[] ) {

	int[] a = { 3,2,2,0,2,3,2,4,2,5,7,9 };

	System.out.println( countN(a, a.length-1, 9) );
	System.out.println( findMin(a, a.length-1) );
    }
}