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package algs11;

import java.util.Arrays;
import stdlib.*;

/**
 * This is a skeleton file for your homework. Edit the sections marked TODO. You
 * may also edit the function "main" to test your code.
 *
 * You must not change the declaration of any method. This will be true of every
 * skeleton file I give you.
 *
 * For example, you will get zero points if you change the line
 * <pre>
 *     public static double minValue (double[] list) {
 * </pre>
 * to something like
 * <pre>
 *     public static void minValue (double[] list) {
 * </pre>
 * or
 * <pre>
 *     public static double minValue (double[] list, int i) {
 * </pre>
 * 
 * Each of the functions below is meant to be SELF CONTAINED. This means that
 * you should use no other functions or classes. You should not use any HashSets
 * or ArrayLists, or anything else! In addition, each of your functions should go
 * through the argument array at most once. The only exception to this
 * removeDuplicates, which is allowed to call numUnique and then go through the
 * array once after that.
 */
public class MyFirstHomeworkFor402 {

  /**
   * minValue returns the minimum value in an array of doubles. You can assume
   * the array is nonempty and has no duplicates. Your solution must go
   * through the array exactly once. Your solution must not call any other
   * functions. Here are some examples (using "==" informally):
   *
   * <pre>
   *   -7  == minValue (new double[] { -7 })
   *    1  == minValue (new double[] { 1, 7, 8, 11 })
   *   -7  == minValue (new double[] { 1, -4, -7, 7, 8, 11 })
   *   -13 == minValue (new double[] { -13, -4, -7, 7, 8, 11 })
   *   -13 == minValue (new double[] { 1, -4, -7, 7, 8, 11, -13 })
   * </pre>
   */
  public static double minValue (double[] list) {
    return StdRandom.uniform (); //TODO: fix this
  }

  /**
   * minPosition returns the position of the minimum value in an array of
   * doubles. The first position in an array is 0 and the last is the
   * array.length-1.
   *
   * You can assume the array is nonempty and has no duplicates. Your solution
   * must go through the array exactly once. Your solution must not call any
   * other functions. Here are some examples (using "==" informally):
   *
   * <pre>
   *   0 == minPosition(new double[] { -7 })
   *   2 == minPosition(new double[] { 1, -4, -7, 7, 8, 11 })
   *   0 == minPosition(new double[] { -13, -4, -7, 7, 8, 11 })
   *   6 == minPosition(new double[] { 1, -4, -7, 7, 8, 11, -9 })
   * </pre>
   */
  public static int minPosition (double[] list) {
    return StdRandom.uniform (100); //TODO: fix this
  }

  /**
   * distanceBetweenMinAndMax returns difference between the minPosition and
   * the maxPosition in an array of doubles.
   *
   * You can assume the array is nonempty and has no duplicates. Your solution
   * must go through the array exactly once. Your solution must not call any
   * other functions. Here are some examples (using "==" informally):
   *
   * <pre>
   *   0 == distanceBetweenMinAndMax(new double[] { -7 })                      // -7,-7 are the min and max
   *   3 == distanceBetweenMinAndMax(new double[] { 1, -4, -7, 7, 8, 11 }),    // -7,11
   *   5 == distanceBetweenMinAndMax(new double[] { -13, -4, -7, 7, 8, 11 })   // -13,11
   *   1 == distanceBetweenMinAndMax(new double[] { 1, -4, -7, 7, 8, 11, -9 }) // -9,11
   * </pre>
   */
  public static int distanceBetweenMinAndMax (double[] list) {
    return StdRandom.uniform (100); //TODO: fix this
  }

  /**
   * numUnique returns the number of unique values in an array of doubles.
   * Unlike the previous questions, the array may be empty and it may contain
   * duplicate values. Also unlike the previous questions, you can assume the
   * array is sorted.
   *
   * Your solution must go through the array exactly once. Your solution must
   * not call any other functions. Here are some examples (using "=="
   * informally):
   *
   * <pre>
   *     0 == numUnique(new double[] { })
   *     1 == numUnique(new double[] { 11 })
   *     1 == numUnique(new double[] { 11, 11, 11, 11 })
   *     8 == numUnique(new double[] { 11, 11, 11, 11, 22, 33, 44, 44, 44, 44, 44, 55, 55, 66, 77, 88, 88 })
   *     8 == numUnique(new double[] { 11, 22, 33, 44, 44, 44, 44, 44, 55, 55, 66, 77, 88 })
   * </pre>
   */
  public static int numUnique (double[] list) {
    return StdRandom.uniform (100); //TODO: fix this
  }

  /**
   * removeDuplicates returns a new array containing the unique values in the
   * array. There should not be any extra space in the array --- there should
   * be exactly one space for each unique element (Hint: numUnique tells you
   * how big the array should be). You may assume that the list is sorted, as
   * you did for numUnique.
   *
   * Your solution may call numUnique, but should not call any other
   * functions. After the call to numUnique, you must go through the array
   * exactly one more time. Here are some examples (using "==" informally):
   *
   * <pre>
   *   new double[] { }
   *     == removeDuplicates(new double[] { })
   *   new double[] { 11 }
   *     == removeDuplicates(new double[] { 11 })
   *     == removeDuplicates(new double[] { 11, 11, 11, 11 })
   *   new double[] { 11, 22, 33, 44, 55, 66, 77, 88 }
   *     == removeDuplicates(new double[] { 11, 11, 11, 11, 22, 33, 44, 44, 44, 44, 44, 55, 55, 66, 77, 88, 88 })
   *     == removeDuplicates(new double[] { 11, 22, 33, 44, 44, 44, 44, 44, 55, 55, 66, 77, 88 })
   * </pre>
   */
  public static double[] removeDuplicates (double[] list) {
    return null; // TODO: fix this
  }

  /**
   * A test program, using private helper functions.  See below.
   * To make typing tests a little easier, I've written a function to convert strings to arrays.  See below.
   */
  public static void main (String[] args) {
    // for minValue: array must be nonempty with unique elements
    testMinValue (11, "11");
    testMinValue (-11, "-11");
    testMinValue (9, "9 11 21 31 41");
    testMinValue (9, "11 9 21 31 41");
    testMinValue (9, "11 21 9 31 41");
    testMinValue (9, "11 21 31 9 41");
    testMinValue (9, "11 21 31 41 9");
    testMinValue (-99, "-99 -11 -21 -31 -41");
    testMinValue (-99, "-11 -99 -21 -31 -41");
    testMinValue (-99, "-11 -21 -99 -31 -41");
    testMinValue (-99, "-11 -21 -31 -99 -41");
    testMinValue (-99, "-11 -21 -31 -41 -99");
    testMinValue (-7, "1 -4 -7 7 8 11 9 -5");   
    testMinValue (-0.5, "0.2 -0.5 -0.1");

    // for minPosition: array must be nonempty with unique elements
    testMinPosition (0, "11");
    testMinPosition (0, "-11");
    testMinPosition (0, "9 11 21 31 41");
    testMinPosition (1, "11 9 21 31 41");
    testMinPosition (2, "11 21 9 31 41");
    testMinPosition (3, "11 21 31 9 41");
    testMinPosition (4, "11 21 31 41 9");
    testMinPosition (0, "-99 -11 -21 -31 -41");
    testMinPosition (1, "-11 -99 -21 -31 -41");
    testMinPosition (2, "-11 -21 -99 -31 -41");
    testMinPosition (3, "-11 -21 -31 -99 -41");
    testMinPosition (4, "-11 -21 -31 -41 -99");
    testMinPosition (2, "1 -4 -7 7 8 11 9 -5");
    testMinPosition (1, "0.2 -0.5 -0.1");
    
    // for distanceBetweenMinAndMax: array must be nonempty with unique elements
    testDistanceBetweenMinAndMax (0, "11");
    testDistanceBetweenMinAndMax (0, "-11");
    testDistanceBetweenMinAndMax (4, "9 11 21 31 41");
    testDistanceBetweenMinAndMax (3, "11 9 21 31 41");
    testDistanceBetweenMinAndMax (2, "11 21 9 31 41");
    testDistanceBetweenMinAndMax (1, "11 21 31 9 41");
    testDistanceBetweenMinAndMax (1, "11 21 31 41 9");
    testDistanceBetweenMinAndMax (4, "9 -11 -21 -31 -41");
    testDistanceBetweenMinAndMax (3, "-11 9 -21 -31 -41");
    testDistanceBetweenMinAndMax (2, "-11 -21 9 -31 -41");
    testDistanceBetweenMinAndMax (1, "-11 -21 -31 9 -41");
    testDistanceBetweenMinAndMax (1, "-11 -21 -31 -41 9");
    testDistanceBetweenMinAndMax (3, "1 -4 -7 7 8 11 9 -5");
    testDistanceBetweenMinAndMax (3, "0.1 -0.4 -0.7 0.7 0.8 1.1 0.9 -0.5");
    
    // for numUnique: array must be sorted
    testNumUnique (0, "");
    testNumUnique (1, "11");
    testNumUnique (1, "11 11 11 11");
    testNumUnique (4, "11 21 31 41");
    testNumUnique (4, "11 11 11 21 31 31 31 31 41");
    testNumUnique (4, "11 21 21 21 31 41 41 41 41");
    testNumUnique (4, "11 11 21 21 21 31 31 41 41 41 41");
    testNumUnique (8, "11 11 11 11 21 31 41 41 41 41 41 51 51 61 71 81 81");
    testNumUnique (8, "11 21 31 41 41 41 41 41 51 51 61 71 81");
    testNumUnique (7, "11 11 11 11 21 31 41 41 41 41 41 51 51 61 71");
    testNumUnique (7, "11 21 31 41 41 41 41 41 51 51 61 71");
    testNumUnique (8, "-81 -81 -81 -81 -71 -61 -51 -51 -51 -51 -41 -41 -31 -21 -11 -11 -11");
    
    // for removeDuplicates: array must be sorted
    testRemoveDuplicates ("", "");
    testRemoveDuplicates ("11", "11");
    testRemoveDuplicates ("11", "11 11 11 11");
    testRemoveDuplicates ("11 21 31 41", "11 21 31 41");
    testRemoveDuplicates ("11 21 31 41", "11 11 11 21 31 31 31 31 41");
    testRemoveDuplicates ("11 21 31 41", "11 21 21 21 31 41 41 41 41");
    testRemoveDuplicates ("11 21 31 41", "11 11 21 21 21 31 31 41 41 41 41");
    testRemoveDuplicates ("11 21 31 41 51 61 71 81", "11 11 11 11 21 31 41 41 41 41 41 51 51 61 71 81 81");
    testRemoveDuplicates ("11 21 31 41 51 61 71 81", "11 21 31 41 41 41 41 41 51 51 61 71 81");
    testRemoveDuplicates ("11 21 31 41 51 61 71", "11 11 11 11 21 31 41 41 41 41 41 51 51 61 71");
    testRemoveDuplicates ("11 21 31 41 51 61 71", "11 21 31 41 41 41 41 41 51 51 61 71");
    testRemoveDuplicates ("-81 -71 -61 -51 -41 -31 -21 -11", "-81 -81 -81 -81 -71 -61 -51 -51 -51 -51 -41 -41 -31 -21 -11 -11 -11");
    StdOut.println ("Finished tests");
  }
  
  /* Test functions --- lot's of similar code! */
  private static void testMinValue (double expected, String list) {
    double[] aList = doublesFromString (list);
    double actual = minValue (aList);
    if (! Arrays.equals (aList, doublesFromString (list))) {
      StdOut.format ("Failed minValue([%s]): Array modified\n", list);
    }
    if (expected != actual) {
      StdOut.format ("Failed minValue([%s]): Expecting (%.1f) Actual (%.1f)\n", list, expected, actual);
    }
  }
  private static void testMinPosition (int expected, String list) {
    double[] aList = doublesFromString (list);
    int actual = minPosition (aList);
    if (! Arrays.equals (aList, doublesFromString (list))) {
      StdOut.format ("Failed minPosition([%s]): Array modified\n", list);
    }
    if (expected != actual) {
      StdOut.format ("Failed minPosition([%s]): Expecting (%d) Actual (%d)\n", list, expected, actual);
    }
  }
  private static void testDistanceBetweenMinAndMax (int expected, String list) {
    double[] aList = doublesFromString (list);
    int actual = distanceBetweenMinAndMax (aList);
    if (! Arrays.equals (aList, doublesFromString (list))) {
      StdOut.format ("Failed distanceBetweenMinAndMax([%s]): Array modified\n", list);
    }
    if (expected != actual) {
      StdOut.format ("Failed distanceBetweenMinAndMax([%s]): Expecting (%d) Actual (%d)\n", list, expected, actual);
    }
  }
  private static void testNumUnique (int expected, String list) {
    double[] aList = doublesFromString (list);
    int actual = numUnique (aList);
    if (! Arrays.equals (aList, doublesFromString (list))) {
      StdOut.format ("Failed numUnique([%s]): Array modified\n", list);
    }
    if (expected != actual) {
      StdOut.format ("Failed numUnique([%s]): Expecting (%d) Actual (%d)\n", list, expected, actual);
    }
  }
  private static void testRemoveDuplicates (String expected, String list) {
    double[] aList = doublesFromString (list);
    double[] actual = removeDuplicates (aList);
    if (! Arrays.equals (aList, doublesFromString (list))) {
      StdOut.format ("Failed removeDuplicates([%s]): Array modified\n", list);
    }
    double[] aExpected = doublesFromString (expected);
    // != does not do what we want on arrays
    if (! Arrays.equals (aExpected, actual)) {
      StdOut.format ("Failed removeDuplicates([%s]): Expecting (%s) Actual (%s)\n", list, Arrays.toString (aExpected), Arrays.toString (actual));
    }
  }
  
  
  /* A utility function to create an array of doubles from a string. */
  // The string should include a list of numbers, separated by single spaces.
  private static double[] doublesFromString (String s) {
    if ("".equals (s)) return new double [0]; // empty array is a special case
    String[] nums = s.split (" ");
    double[] result = new double[nums.length];
    for (int i = nums.length-1; i >= 0; i--) {
      try { 
        result[i] = Double.parseDouble (nums[i]); 
      } catch (NumberFormatException e) { 
        throw new IllegalArgumentException (String.format ("Bad argument \"%s\": could not parse \"%s\" as a double", s, nums[i]));
      }
    }
    return result;
  }
}