Eric Boyd IntList

IntListReview.iml

@@ -7,5 +7,37 @@
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="module-library" scope="TEST">
+      <library name="JUnit5.8.1">
+        <CLASSES>
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter/5.8.1/junit-jupiter-5.8.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.8.1/junit-jupiter-api-5.8.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.8.1/junit-platform-commons-1.8.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.2/apiguardian-api-1.1.2.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-params/5.8.1/junit-jupiter-params-5.8.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-engine/5.8.1/junit-jupiter-engine-5.8.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.8.1/junit-platform-engine-1.8.1.jar!/" />
+        </CLASSES>
+        <JAVADOC />
+        <SOURCES />
+      </library>
+    </orderEntry>
+    <orderEntry type="module-library">
+      <library>
+        <CLASSES>
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter/5.8.1/junit-jupiter-5.8.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.8.1/junit-jupiter-api-5.8.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.8.1/junit-platform-commons-1.8.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.2/apiguardian-api-1.1.2.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-params/5.8.1/junit-jupiter-params-5.8.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-engine/5.8.1/junit-jupiter-engine-5.8.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.8.1/junit-platform-engine-1.8.1.jar!/" />
+        </CLASSES>
+        <JAVADOC />
+        <SOURCES />
+      </library>
+    </orderEntry>
   </component>
 </module>

src/ArrayIntList.java

@@ -0,0 +1,199 @@
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+public class ArrayIntList  implements  IntList
+{
+    private int[] buffer;
+    private int size;
+    public ArrayIntList()
+    {
+        buffer = new int[10];
+        size = 0;
+    }
+
+    @Override
+    // Normally fast (constant time unless you have to resize)
+    public void addBack(int value)
+    {
+        checkSize();
+        buffer[size] = value;
+        size++;
+    }
+
+    @Override
+    //Slow must move every element in array O(N)
+    public void addFront(int value)
+    {
+        checkSize();
+        add(0, value);
+    }
+
+    @Override
+    //Slow, must move every element in array located above entry index O(N)
+    public void add(int index, int value)
+    {
+        checkSize();
+        size ++;
+        checkIndex(index);
+        for(int i = size; i > index;  i--)
+        {
+            buffer[i] = buffer[i-1];
+        }
+        buffer[index] = value;
+    }
+
+    @Override
+    // Fast, constant time.
+    public void removeBack()
+    {
+        if(size == 0)
+        {
+            throw new IndexOutOfBoundsException("Attempt to remove from empty arrayList.");
+        }
+        size--;
+    }
+
+    @Override
+    //Slow must move every element in array O(N)
+    public void removeFront()
+    {
+        remove(0);
+    }
+
+    @Override
+    //Slow, must move every element in array located above entry index O(N)
+    public int remove(int index)
+    {
+        if(size == 0)
+        {
+            throw new IndexOutOfBoundsException("Attempt to remove from empty arrayList.");
+        }
+        checkIndex(index);
+        int returnInt = buffer[index];
+        for(int i = index; i < size;  i++)
+        {
+            buffer[i] = buffer[i + 1];
+        }
+        size --;
+        return returnInt;
+    }
+
+    @Override
+    //Very fast operation. O(1) constant time
+    public int get(int index)
+    {
+        checkIndex(index);
+        return buffer[index];
+    }
+
+    @Override
+    public boolean contains(int value)
+    {
+        return indexOf(value) >= 0;
+    }
+
+    @Override
+    public int indexOf(int value)
+    {
+        for (int i = 0; i < size; i++)
+        {
+           if(buffer[i] == value) {
+               return i;
+           }
+        }
+        return -1;
+    }
+
+    @Override
+    public boolean isEmpty()
+    {
+        return size == 0;
+    }
+
+    @Override
+    public int size()
+    {
+        return size;
+    }
+
+    @Override
+    public void clear()
+    {
+        buffer = new int[10];
+        size = 0;
+    }
+    private void checkIndex(int index) throws IndexOutOfBoundsException
+    {
+        if(index >= size || index < 0)
+        {
+            throw new IndexOutOfBoundsException(index + " is outside Array.");
+        }
+    }
+
+    public String toString()
+    {
+        if(size == 0)
+        {
+            return "[]";
+        }
+        else
+        {
+            StringBuilder returnString = new StringBuilder();
+            returnString.append("[").append(buffer[0]);
+            for(int i = 1; i < size; i++)
+            {
+                returnString.append(", ").append(buffer[i]);
+            }
+            returnString.append("]");
+            return returnString.toString();
+        }
+    }
+    private void checkSize()
+    {
+        if(size > buffer.length - 2)
+        {
+            buffer = resize();
+        }
+    }
+    // Slow because you must "touch" every element in array to copy to new array O(N)
+    private int[] resize() {
+        int[] returnInt = new int[buffer.length * 2];
+
+        for (int i = 0; i < size; i++)
+        {
+            returnInt[i] = buffer[i];
+        }
+        return returnInt;
+    }
+
+    @Override
+    public Iterator<Integer> iterator() {
+        return new ArrayIntListIterator();
+    }
+
+    private class ArrayIntListIterator implements Iterator<Integer>
+    {
+      private int position;
+
+      public ArrayIntListIterator()
+      {
+          position = 0;
+      }
+
+      public boolean hasNext()
+      {
+          return position != size;
+      }
+
+      public Integer next()
+      {
+          if(hasNext())
+          {
+              Integer output = buffer[position];
+              position++;
+              return output;
+          }
+          throw new NoSuchElementException("No elements left.");
+      }
+    }
+}