package algs11;
import stdlib.*;
import java.util.Arrays;
/*
 PROBLEM 1: Run the program algs11.XAutoboxingValueOf and answer the following questions.

   QUESTION: What is the difference between the following two statements:
     x = "Dog";
     x = new String("Dog");

   ANSWER:

   QUESTION: What is the difference between the following two statements:
     x = Integer.valueOf (3);
     x = new Integer (3);

   ANSWER:

   QUESTION: Aside from the difference in the numbers,
   what is the difference between the following two statements:
     x = Integer.valueOf (12);
     x = Integer.valueOf (132973);

   ANSWER:

 PROBLEM 2: Using the formula given in class, write recursive versions of "average", "copy" and
"reverse", using the iterative versions below as a starting point.  The iterative versions are
"averageI", "plusOneI" and "reverseI".  HINT: You will need to define helper functions.
 */
public class MyArrayFunctions {

	public static double max (double[] a) {
		return 0.0; // TODO
	}
	public static double maxI (double[] a) {
		int N = a.length;
		double result = Double.NEGATIVE_INFINITY;
		for (int i = 0; i < N; i++)
			if (a[i] > result) result = a[i];
		return result;
	}

	public static double[] plusOne (double[] a) {
		return null; //TODO
	}
	public static double[] plusOneI (double[] a) {
		int N = a.length;
		double[] result = new double[N];
		for (int i = 0; i < N; i++)
			result[i] = a[i] + 1;
		return result;
	}

	public static void reverse (double[] a) {
		return; //TODO
	}
	public static void reverseI (double[] a) {
		int N = a.length;
		for (int i = 0; i < N / 2; i++) {
			double temp = a[i];
			a[i] = a[N - 1 - i];
			a[N - i - 1] = temp;
		}
	}

	public static void test (double[] a) {
		StdOut.format ("max: %f\n", maxI (a));
		double[] b = plusOne (a);
		StdOut.format ("plusOne: %s\n", Arrays.toString (b));
		reverse (a);
		StdOut.format ("reverse: %s\n", Arrays.toString (a));
	}
	public static void testI (double[] a) {
		StdOut.format ("max: %f\n", maxI (a));
		double[] b = plusOneI (a);
		StdOut.format ("plusOne: %s\n", Arrays.toString (b));
		reverseI (a);
		StdOut.format ("reverse: %s\n", Arrays.toString (a));
	}
	public static void main (String[] args) {
		test(new double[] { 10, 20, 60, 40, 50 });
		test(new double[] { 60, 20, 30, 40 });
		test(new double[] { 10, 20, 60 });
		test(new double[] { 10, 20 });
		test(new double[] { 10 });
		test(new double[] { });
	}
}