IntList: Resizing Array Implementation

IntListReview.iml

@@ -4,8 +4,25 @@
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/tests" isTestSource="true" />
     </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>
   </component>
 </module>

src/ArrayIntList.java

@@ -0,0 +1,297 @@
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+public class ArrayIntList implements IntList {
+
+    //fields:
+    private int size;
+    private int[] buffer;
+
+    public ArrayIntList()
+    {
+        //initialize my fields
+        size = 0;
+        buffer = new int[10];
+    }
+
+    /**
+     * Prepends (inserts) the specified value at the front of the list (at index 0).
+     * Shifts the value currently at the front of the list (if any) and any
+     * subsequent values to the right.
+     *
+     * @param value value to be inserted
+     */
+    @Override
+    public void addFront(int value) {
+        if(size == buffer.length)
+        {
+            resize(size * 2);
+        }
+
+        for(int i = size; i >= 1; i--)
+        {
+            buffer[i] = buffer[i-1];
+        }
+        buffer[0] = value;
+        size++;
+    }
+
+    /**
+     * Appends (inserts) the specified value at the back of the list (at index size()-1).
+     *
+     * @param value value to be inserted
+     */
+    @Override
+    public void addBack(int value) {
+        //TODO: check to see if we are full - if so, we need to create a larger buffer
+        if(size == buffer.length)
+        {
+            resize(size * 2);
+        }
+
+        buffer[size] = value;
+        size++;
+    }
+
+    /**
+     * Inserts the specified value at the specified position in this list.
+     * Shifts the value currently at that position (if any) and any subsequent
+     * values to the right.
+     *
+     * @param index index at which the specified value is to be inserted
+     * @param value value to be inserted
+     * @throws IndexOutOfBoundsException if the index is out of range
+     */
+    @Override
+    public void add(int index, int value) {
+        if(index > size || index < 0)
+        {
+            throw new IndexOutOfBoundsException("Invalid index");
+        }
+        if(size == buffer.length)
+        {
+            resize(size * 2);
+        }
+        if(index == size)
+        {
+            buffer[index] = value;
+        }
+        else {
+            for(int i = size; i >= index; i--)
+            {
+                buffer[i] = buffer[i-1];
+            }
+            buffer[index] = value;
+        }
+        size++;
+    }
+
+    /**
+     * Removes the value located at the front of the list
+     * (at index 0), if it is present.
+     * Shifts any subsequent values to the left.
+     */
+    @Override
+    public void removeFront() {
+        if(!isEmpty())
+        {
+            for (int i = 0; i <= size - 2; i++) {
+                buffer[i] = buffer[i + 1];
+            }
+            buffer[size - 1] = 0;
+            size--;
+        }
+    }
+
+    /**
+     * Removes the value located at the back of the list
+     * (at index size()-1), if it is present.
+     */
+    @Override
+    public void removeBack() {
+        if(!isEmpty())
+        {
+            buffer[size-1] = 0;
+            size--;
+            return;
+        }
+       throw new NoSuchElementException("There are no elements to remove!");
+    }
+
+    /**
+     * Removes the value at the specified position in this list.
+     * Shifts any subsequent values to the left. Returns the value
+     * that was removed from the list.
+     *
+     * @param index the index of the value to be removed
+     * @return the value previously at the specified position
+     * @throws IndexOutOfBoundsException if the index is out of range
+     */
+    @Override
+    public int remove(int index) {
+        //check to see if index is valid
+        if(index >= size || index < 0)
+        {
+            throw new IndexOutOfBoundsException("Invalid index");
+        }
+        // save a copy of the value to be returned later
+        int removedValue = buffer[index];
+
+        //shift values to the left
+        for (int i = index; i < size; i++) {
+            buffer[i] = buffer[i+1];
+        }
+        //remove the final index value
+        buffer[size - 1] = 0;
+        //decrement size
+        size--;
+        //return the removed value
+        return removedValue;
+    }
+
+    /**
+     * Returns the value at the specified position in the list.
+     *
+     * @param index index of the value to return
+     * @return the value at the specified position in this list
+     * @throws IndexOutOfBoundsException if the index is out of range
+     */
+    @Override
+    public int get(int index) {
+        if(index > size)
+        {
+            throw new IndexOutOfBoundsException();
+        }
+        return buffer[index];
+    }
+
+    /**
+     * Returns true if this list contains the specified value.
+     *
+     * @param value value whose presence in this list is to be searched for
+     * @return true if this list contains the specified value
+     */
+    @Override
+    public boolean contains(int value) {
+        for (int i = 0; i < size; i++) {
+            if(buffer[i] == value)
+            {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Returns the index of the first occurrence of the specified value
+     * in this list, or -1 if this list does not contain the value.
+     *
+     * @param value value to search for
+     * @return the index of the first occurrence of the specified value in this list
+     * or -1 if this list does not contain the value
+     */
+    @Override
+    public int indexOf(int value) {
+        for (int i = 0; i < size; i++) {
+            if(buffer[i] == value)
+            {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    /**
+     * Returns true if this list contains no values.
+     *
+     * @return true if this list contains no values
+     */
+    @Override
+    public boolean isEmpty() {
+        return size == 0;
+    }
+
+    /**
+     * Returns the number of values in this list.
+     *
+     * @return the number of values in this list
+     */
+    @Override
+    public int size() {
+        return size;
+    }
+
+    /**
+     * Removes all the values from this list.
+     * The list will be empty after this call returns.
+     */
+    @Override
+    public void clear() {
+        buffer = new int[buffer.length];
+        size = 0;
+    }
+
+    private void resize(int newSize)
+    {
+        int[] newBuffer = new int[newSize];
+
+        for (int i = 0; i < size; i++) {
+            newBuffer[i] = buffer[i];
+        }
+        //set the new space into the buffer
+        buffer = newBuffer;
+
+        //the old space is no longer "pointed to" and will eventually
+        //be cleaned up by the garbage collector
+    }
+
+    /**
+     * Returns an iterator over elements of type {@code T}.
+     *
+     * @return an Iterator.
+     */
+    @Override
+    public Iterator<Integer> iterator() {
+        return new IntListIterator();
+    }
+
+    //create a private helper Iterator class
+    private class IntListIterator implements Iterator<Integer>{
+        //private fields
+        private int i;
+
+        private IntListIterator(){
+            i = 0;
+        }
+
+
+        /**
+         * Returns {@code true} if the iteration has more elements.
+         * (In other words, returns {@code true} if {@link #next} would
+         * return an element rather than throwing an exception.)
+         *
+         * @return {@code true} if the iteration has more elements
+         */
+        @Override
+        public boolean hasNext() {
+            return i < size;
+        }
+
+        /**
+         * Returns the next element in the iteration.
+         *
+         * @return the next element in the iteration
+         * @throws NoSuchElementException if the iteration has no more elements
+         */
+        @Override
+        public Integer next() {
+            if(i >= size)
+            {
+                throw new NoSuchElementException("i is out of bounds");
+            }
+            int currentValue = buffer[i];
+            i++;
+            return currentValue;
+        }
+    }
+}