From 42a06346c842b46f84e1d44303691dfc998df629 Mon Sep 17 00:00:00 2001
From: blank <blank@caltech.edu>
Date: Wed, 18 Jan 2023 16:31:46 -0800
Subject: [PATCH] After lecture 05.
---
00/IntBag.java | 3 +-
05/ArraySet.java | 95 +++++++++++++++++++++++++++++++++++++++++++
05/ArraySetMain.java | 17 ++++++++
05/ArraySetTests.java | 46 +++++++++++++++++++++
05/ISet.java | 13 ++++++
05/Person.java | 22 ++++++++++
6 files changed, 195 insertions(+), 1 deletion(-)
create mode 100644 05/ArraySet.java
create mode 100644 05/ArraySetMain.java
create mode 100644 05/ArraySetTests.java
create mode 100644 05/ISet.java
create mode 100644 05/Person.java
diff --git a/00/IntBag.java b/00/IntBag.java
index 20012d3..5ea283b 100644
--- a/00/IntBag.java
+++ b/00/IntBag.java
@@ -48,6 +48,7 @@ public class IntBag {
*/
public int pick() {
Random r = new Random();
- return this.list.get(r.nextInt(min - 1, max));
+ //return this.list.get(r.nextInt(min - 1, max));
+ return 0;
}
}
diff --git a/05/ArraySet.java b/05/ArraySet.java
new file mode 100644
index 0000000..882c3ca
--- /dev/null
+++ b/05/ArraySet.java
@@ -0,0 +1,95 @@
+import java.util.Iterator;
+
+public class ArraySet<E> implements ISet<E> {
+ private static final int DEFAULT_CAPACITY = 10;
+ private static final double GROW_FACTOR = 2.0;
+ private E[] data;
+ private int size;
+
+ public ArraySet() {
+ this.data = (E[])new Object[DEFAULT_CAPACITY];
+ }
+
+ private void ensureCapacity(int size) {
+ if (this.capacity() < size) {
+ E[] newData = (E[])new Object[(int)(this.capacity()*GROW_FACTOR)];
+ for (int i = 0; i < this.size; i++) {
+ newData[i] = this.data[i];
+ }
+ this.data = newData;
+ }
+ }
+
+ private int capacity() {
+ return this.data.length;
+ }
+
+ public int size() {
+ return this.size;
+ }
+
+ @Override
+ public void add(E elem) {
+ if (!this.contains(elem)) {
+ this.ensureCapacity(this.size + 1);
+ this.data[this.size] = elem;
+ this.size++;
+ }
+
+ }
+
+ @Override
+ public boolean isEmpty() {
+ return this.size == 0;
+ }
+
+ @Override
+ public Iterator<E> iterator() {
+ return new ArraySetIterator();
+ }
+
+ /*
+ [1, 2, 3]
+
+ idx=0, next() => 1
+ idx=1
+ hasNext() 1 < 3 true
+ idx=1, next() => 2
+ hasNext() 2 < 3 true
+
+ */
+
+ private class ArraySetIterator implements Iterator<E> {
+ private int idx;
+ public ArraySetIterator() {
+ this.idx = 0;
+ }
+
+ @Override
+ public boolean hasNext() {
+ return this.idx < size();
+ }
+
+ @Override
+ public E next() {
+ E toReturn = data[this.idx];
+ this.idx++;
+ return toReturn;
+ }
+ }
+
+ @Override
+ public String toString() {
+ if (this.isEmpty()) {
+ return "[]";
+ }
+
+ String result = "[";
+ for (int i = 0; i < this.size; i++) {
+ result += this.data[i] + ", ";
+ }
+
+ result = result.substring(0, result.length() - 2);
+ return result + "]";
+ }
+}
\ No newline at end of file
diff --git a/05/ArraySetMain.java b/05/ArraySetMain.java
new file mode 100644
index 0000000..420d256
--- /dev/null
+++ b/05/ArraySetMain.java
@@ -0,0 +1,17 @@
+import java.util.Iterator;
+
+public class ArraySetMain {
+ public static void main(String[] args) {
+ ISet<Integer> set = new ArraySet<>();
+ set.add(1);
+ set.add(0);
+ System.out.println(set.contains(0));
+
+ Iterator<Integer> iterator = set.iterator();
+ while (iterator.hasNext()) {
+ Integer i = iterator.next();
+ System.out.println(i);
+ }
+
+ }
+}
diff --git a/05/ArraySetTests.java b/05/ArraySetTests.java
new file mode 100644
index 0000000..862d695
--- /dev/null
+++ b/05/ArraySetTests.java
@@ -0,0 +1,46 @@
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class ArraySetTests {
+ @Test
+ public void simpleSizeTest() {
+ ISet<Integer> set = new ArraySet<>();
+ set.add(0);
+ set.add(0);
+ set.add(0);
+ set.add(0);
+ set.add(0);
+ assertEquals(1, set.size(), "repeatedly adding the same element results in it only being added once");
+ }
+
+ @Test
+ public void simpleToStringTest() {
+ ISet<Integer> set = new ArraySet<>();
+ assertEquals("[]", set.toString(), "adding consecutive values results in the right string output");
+
+ set.add(0);
+ assertEquals("[0]", set.toString(), "adding consecutive values results in the right string output");
+
+ set.add(1);
+ assertEquals("[0, 1]", set.toString(), "adding consecutive values results in the right string output");
+
+ set.add(2);
+ assertEquals("[0, 1, 2]", set.toString(), "adding consecutive values results in the right string output");
+
+ set.add(3);
+ assertEquals("[0, 1, 2, 3]", set.toString(), "adding consecutive values results in the right string output");
+ }
+
+ @Test
+ public void peopleTest() {
+ ISet<Person> set = new ArraySet<>();
+ assertEquals("[]", set.toString(), "adding person values results in the right string output");
+ Person p = new Person("Adam");
+ set.add(p);
+ assertEquals("[Adam]", set.toString(), "adding person values results in the right string output");
+
+ set.add(p);
+ assertEquals("[Adam]", set.toString(), "adding person values results in the right string output");
+ }
+}
\ No newline at end of file
diff --git a/05/ISet.java b/05/ISet.java
new file mode 100644
index 0000000..c9d73ad
--- /dev/null
+++ b/05/ISet.java
@@ -0,0 +1,13 @@
+public interface ISet<E> extends Iterable<E> {
+ public int size();
+ public default boolean contains(E elem) {
+ for (E x : this) {
+ if (x.equals(elem)) {
+ return true;
+ }
+ }
+ return false;
+ }
+ public void add(E elem);
+ public boolean isEmpty();
+}
diff --git a/05/Person.java b/05/Person.java
new file mode 100644
index 0000000..2b42447
--- /dev/null
+++ b/05/Person.java
@@ -0,0 +1,22 @@
+public class Person {
+ private String name;
+
+ public Person(String name) {
+ this.name = name;
+ }
+
+ public String getName() {
+ return this.name;
+ }
+
+ public String toString() {
+ return this.getName();
+ }
+
+ public boolean equals(Object o) {
+ if (!(o instanceof Person)) {
+ return false;
+ }
+ return ((Person)o).name.equals(this.name);
+ }
+}
--
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