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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[] { });
  }
}