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Chapter 19 Completed
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‎README.md

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16</strong></a> - JavaFx UI Controls and Multimedia</li><br>
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<li><a href="https://github.com/HarryDulaney/intro-to-java-programming/tree/master/ch_17"><strong>Chapter 17</strong></a> - Binary I/O (Complete)</li><br>
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<li><a href="https://github.com/HarryDulaney/intro-to-java-programming/tree/master/ch_18"><strong>Chapter 18</strong></a> - Recursion</li><br>
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<li><a href="https://github.com/HarryDulaney/intro-to-java-programming/tree/master/ch_19"><strong>Chapter 19</strong></a> - Generics</li><br>
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<li><a href="https://github.com/HarryDulaney/intro-to-java-programming/tree/master/ch_19"><strong>Chapter 19</strong></a> - Generics (Complete)</li><br>
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<li><a href="https://github.com/HarryDulaney/intro-to-java-programming/tree/master/ch_20"><strong>Chapter 20</strong></a> - Lists, Stacks, Queues, and Priority Queues</li><br>
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<li><a href="https://github.com/HarryDulaney/intro-to-java-programming/tree/master/ch_21"><strong>Chapter 21</strong></a> - Sets and Maps</li><br>
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<li><!--<a href="https://github.com/HarryDulaney/java-programming-daniel-liang-10th/tree/master/">--><strong>Chapter 22</strong><!--</a>--> - Developing Efficient Algorithms</li><br>

‎ch_18/Exercise18_25.java

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@@ -43,7 +43,7 @@ public static void displayPermutation(String s1, String s2) {
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if (s2.length() > 0) {
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for (int i = 0; i < s2.length(); i++) {
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String shuffle1 = s1 + s2.charAt(i);
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String shuffle2 = s2.substring(0, i) + s1.substring(i + 1);
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String shuffle2 = s2.substring(0, i) + s2.substring(i + 1);
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displayPermutation(shuffle1, shuffle2);
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}
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} else {

‎ch_19/Exercise19_06.java

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package ch_19;
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import java.util.Arrays;
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/**
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* 19.6 (Maximum element in a two-dimensional array) Write a generic method that
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* returns the maximum element in a two-dimensional array.
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* public static <E extends Comparable<E>> E max(E[][] list)
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*/
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public class Exercise19_06 {
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public static void main(String[] args) {
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Double[][] values = new Double[][]{
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{100.1, 100.3, 555.12},
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{100.0, 100.8, 100.6},
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{65656.22, 1112.34, 99.9}
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};
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System.out.println("Generic Max method returned: " + max(values) + ". When passed this two-dimensional Array " +
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"of values: ");
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for (Double[] valArray: values) {
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System.out.println(Arrays.toString(valArray));
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}
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}
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public static <E extends Comparable<E>> E max(E[][] list) {
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E maxValue = list[0][0];
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for (int i = 0; i < list.length; i++) {
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for (int j = 0; j < list[i].length; j++) {
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if (list[i][j].compareTo(maxValue) > 0) {
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maxValue = list[i][j];
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}
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}
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}
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return maxValue;
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}
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}

‎ch_19/Exercise19_07.java

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package ch_19;
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import java.util.Arrays;
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/**
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* 19.7 (Generic binary search) Implement the following method using binary search.
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* public static <E extends Comparable<E>> int binarySearch(E[] list, E key)
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*/
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public class Exercise19_07 {
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public static void main(String[] args) {
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Double searchKey = 111.11;
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Double[] values = new Double[]{4400.1, 1203.3, 3100.0, 18700.8, 4100.6, 111.11, 2222.21, 4529.21};
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System.out.println("Generic Binary Search method found the search key value: " + searchKey + " at index: " + binarySearch(values,
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searchKey) + " in the above array.");
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}
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public static <E extends Comparable<E>> int binarySearch(E[] list, E key) {
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System.out.println("Sorting the array to ensure binarySearch is supported: ");
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Arrays.sort(list);
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System.out.println(Arrays.toString(list));
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int lowIdx = 0; // First element in the array
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int highIdx = list.length - 1; // Last element in the array
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while (highIdx >= lowIdx) {
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int midIdx = (lowIdx + highIdx) / 2;
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int compare = key.compareTo(list[midIdx]); // Compare key to value at midIdx
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if (compare < 0) { // Key is less than list[midIdx]
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highIdx = midIdx - 1; // Value can only be to the left of list[midIdx]
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} else if (compare == 0) { // Key equals list[midIdx]
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return midIdx; // Return the index of matched value
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} else { // Key is greater than list[midIdx]
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lowIdx = midIdx + 1; // Value can only be to the right of list[midIdx]
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}
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}
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return -1; // No matching value found in list
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}
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}

‎ch_19/Exercise19_08.java

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package ch_19;
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import java.util.ArrayList;
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import java.util.Arrays;
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/**
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* 19.8 (Shuffle ArrayList) Write the following method that shuffles an ArrayList:
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* public static <E> void shuffle(ArrayList<E> list)
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*/
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public class Exercise19_08 {
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public static void main(String[] args) {
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//Test generic method with Double values
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ArrayList<Double> doubleList =
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new ArrayList<>(Arrays.asList(1.1, 2.2, 3.3, 4.4, 5.5, 6.6, 7.7, 8.8));
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//Test generic method with Integer values
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ArrayList<Integer> integerList =
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new ArrayList<>(Arrays.asList(11, 22, 33, 44, 55, 66, 77, 88));
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System.out.println("Before shuffling the ArrayList of Doubles is: " + doubleList);
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shuffle(doubleList);
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System.out.println("After performing Generic shuffle: " + doubleList);
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System.out.println("Before shuffling the ArrayList of Integers is: " + integerList);
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shuffle(integerList);
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System.out.println("After performing Generic shuffle: " + integerList);
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}
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public static <E> void shuffle(ArrayList<E> list) {
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for (int i = 0; i < list.size() && !list.isEmpty(); i++) { // Loop through ArrayList
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int randomIdx = (int) (Math.random() * (list.size() - 1));
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// Swap random values
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E value = list.get(i); // Get value in array at index i
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E temp = list.get(randomIdx); // Get value at random index
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list.set(randomIdx, value); // Set value to randomIdx
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list.set(i, temp); // Set value from randomIdx to index i
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}
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}
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}

‎ch_19/Exercise19_09.java

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package ch_19;
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import java.util.ArrayList;
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import java.util.Arrays;
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/**
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* 19.9 (Sort ArrayList) Write the following method that sorts an ArrayList:
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* public static <E extends Comparable<E>> void sort(ArrayList<E> list)
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*/
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public class Exercise19_09 {
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public static void main(String[] args) {
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//Test generic method with Double values
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ArrayList<Double> doubleList =
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new ArrayList<>(Arrays.asList(5.0, 7.0, 1.0, 9.0, 10.0, 6.0, 2.0, 4.0, 3.0, 8.0));
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//Test generic method with Integer values
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ArrayList<Integer> integerList =
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new ArrayList<>(Arrays.asList(55, 99, 66, 33, 100, 11, 77, 44, 88, 22));
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System.out.println("Before sorting the ArrayList of Doubles is: " + doubleList);
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sort(doubleList);
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System.out.println("After performing Generic sort: " + doubleList);
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System.out.println("Before sorting the ArrayList of Integers is: " + integerList);
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sort(integerList);
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System.out.println("After performing Generic sort: " + integerList);
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}
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public static <E extends Comparable<E>> void sort(ArrayList<E> list) {
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boolean loop = true;
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while (loop) {
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loop = false;
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for (int i = 0; i < list.size() - 1; i++) {
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if (list.get(i).compareTo(list.get(i + 1)) > 0) {
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loop = true;
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E temp = list.get(i);
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list.set(i, list.get(i + 1));
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list.set(i + 1, temp);
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}
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}
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}
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}
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}

‎ch_19/Exercise19_10.java

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package ch_19;
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import java.util.ArrayList;
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import java.util.Arrays;
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/**
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* 19.10 (Largest element in ArrayList)
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* Write the following method that returns the largest
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* element in an ArrayList:
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* <p>
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* public static <E extends Comparable<E>> E max(ArrayList<E> list)
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*/
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public class Exercise19_10 {
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public static void main(String[] args) {
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//Test generic method with Double values
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ArrayList<Double> doubleList =
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new ArrayList<>(Arrays.asList(4400.0, 2.2, 6.6, 4400.1, 4.4, 7.7, 1.1, 8.8, 3.3, 5.5, 1203.3, 4400.2,
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4400.6, 55.2));
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//Test generic method with Integer values
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ArrayList<Integer> integerList =
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new ArrayList<>(Arrays.asList(55, 66, 33, 11, 77, 44, 88, 22));
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System.out.println("The max(ArrayList<E> list) method with a list Doubles returned: " + max(doubleList));
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System.out.println("The max(ArrayList<E> list) method with a list of Integers returned: " + max(integerList));
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}
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public static <E extends Comparable<E>> E max(ArrayList<E> list) {
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if (!list.isEmpty()) {
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E maxValue = list.get(0); // Initialize Max
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for (int i = 1; i < list.size(); i++) {
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E nextValue = list.get(i); // Initialize next value in list
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if (maxValue.compareTo(nextValue) < 0) { // If maxValue is less than nextValue compareTo() returns -1;
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maxValue = list.get(i); // Set larger value to maxValue
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}
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}
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return maxValue;
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}
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throw new IllegalArgumentException("public static <E extends Comparable<E>> E max(ArrayList<E> list) must be " +
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"passed a NON-empty list.");
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}
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}
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‎ch_19/exercise19_11/Complex.java

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package ch_19.exercise19_11;
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/**
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* The Complex.class from Programming Exercise 13.17
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*/
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public class Complex extends Number implements Cloneable {
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private double a;
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private double b;
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private static double i = Math.sqrt(-1);
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public Complex() {
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this(0);
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}
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public Complex(double a) {
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this(a, 0);
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}
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public Complex(double a, double b) {
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this.a = a;
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this.b = b;
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}
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/**
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* Example addition: (a + bi) + (c + di) = (a + c) + (b + d)i
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*
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* @param complex Complex number to add
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* @return the addition result
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*/
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public double add(Complex complex) {
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return (this.a + complex.a) + (this.b + complex.b) * i;
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}
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/**
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* Subtract example:
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* a + bi - (c + di) = (a - c) + (b - d)i
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*
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* @param complex
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* @return
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*/
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public double subtract(Complex complex) {
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return (this.a - complex.a) + (this.b - complex.b) * i;
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}
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/**
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* (a + bi)*(c + di) = (ac - bd) + (bc + ad)i
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*
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* @param complex
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* @return
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*/
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public double multiply(Complex complex) {
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return (this.a * complex.a - this.b * complex.b) + ((this.b * complex.a + this.a * complex.b) * i);
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}
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/**
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* (a + bi)/(c + di) = (ac + bd)/(c2 + d2) + (bc - ad)i/(c2 + d2)
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*
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* @param complex
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* @return
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*/
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public double divide(Complex complex) {
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return (this.a * complex.a + this.b * complex.b) / (Math.pow(complex.a, 2) + Math.pow(complex.b, 2)) + ((this.b * complex.a - this.a * complex.b) * i) / (Math.pow(complex.a, 2) + Math.pow(complex.b, 2));
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}
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public double abs(Complex complex) {
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return Math.sqrt(Math.pow(this.a, 2) + Math.pow(this.b, 2));
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}
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public double getRealPart() {
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return a;
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}
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public double getImaginaryPart() {
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return b * i;
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}
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@Override
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public Complex clone() throws CloneNotSupportedException {
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return (Complex) super.clone();
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}
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@Override
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public int intValue() {
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return (int) Math.round(a + b * i);
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}
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@Override
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public long longValue() {
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return Math.round(a + b * i);
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}
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@Override
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public float floatValue() {
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return (float) (a + b * i);
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}
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@Override
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public double doubleValue() {
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return a + b * i;
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}
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@Override
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public String toString() {
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return "( " + a + " + " + b + "(" + i + ")" + " )";
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}
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}

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