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-rw-r--r--csci1913/Java/lab6/lab6/Polygon.java (renamed from csci1913/Java/lab6/Polygon.java)0
-rw-r--r--csci1913/Java/lab6/lab6/lab6_strap012.java (renamed from csci1913/Java/lab6/lab6_strap012.java)0
-rw-r--r--csci1913/Java/lab6/lab6/tests6.java (renamed from csci1913/Java/lab6/tests6.java)0
-rw-r--r--csci1913/Java/lab9_strap012.java139
4 files changed, 139 insertions, 0 deletions
diff --git a/csci1913/Java/lab6/Polygon.java b/csci1913/Java/lab6/lab6/Polygon.java
index 7f025fe..7f025fe 100644
--- a/csci1913/Java/lab6/Polygon.java
+++ b/csci1913/Java/lab6/lab6/Polygon.java
diff --git a/csci1913/Java/lab6/lab6_strap012.java b/csci1913/Java/lab6/lab6/lab6_strap012.java
index feecbe1..feecbe1 100644
--- a/csci1913/Java/lab6/lab6_strap012.java
+++ b/csci1913/Java/lab6/lab6/lab6_strap012.java
diff --git a/csci1913/Java/lab6/tests6.java b/csci1913/Java/lab6/lab6/tests6.java
index fc98648..fc98648 100644
--- a/csci1913/Java/lab6/tests6.java
+++ b/csci1913/Java/lab6/lab6/tests6.java
diff --git a/csci1913/Java/lab9_strap012.java b/csci1913/Java/lab9_strap012.java
new file mode 100644
index 0000000..94a003c
--- /dev/null
+++ b/csci1913/Java/lab9_strap012.java
@@ -0,0 +1,139 @@
+import java.util.Iterator;
+
+// ARRAY QUEUE. A fixed length queue implemented as a circular array.
+
+class ArrayQueue<Base> {
+ private int front; // Index of front object in BASES.
+ private int rear; // Index of rear object in BASES.
+ private Base[] bases; // The BASEs in the queue.
+
+ // Constructor. Make a new empty queue that can hold SIZE - 1 elements.
+
+ public ArrayQueue(int size) {
+ if (size >= 1) {
+ front = 0;
+ rear = 0;
+ bases = (Base[]) new Object[size];
+ } else {
+ throw new IllegalArgumentException("Size must be at least 1.");
+ }
+ }
+
+ // DEQUEUE. Remove a BASE from the front of the queue and return it.
+
+ public Base dequeue() {
+ if (isEmpty()) {
+ throw new IllegalStateException("Queue is empty.");
+ } else {
+ front = (front + 1) % bases.length;
+ Base temp = bases[front];
+ bases[front] = null;
+ return temp;
+ }
+ }
+
+ // ENQUEUE. Add BASE to the rear of the queue.
+
+ public void enqueue(Base base) {
+ int nextRear = (rear + 1) % bases.length;
+ if (front == nextRear) {
+ throw new IllegalStateException("Queue is full.");
+ } else {
+ rear = nextRear;
+ bases[rear] = base;
+ }
+ }
+
+ // IS EMPTY. Test if the queue is empty.
+
+ public boolean isEmpty() {
+ return front == rear;
+ }
+
+ // IS FULL. Test if the queue can hold no more elements.
+
+ public boolean isFull() {
+ return front == (rear + 1) % bases.length;
+ }
+
+ private class ArrayQueueIterator implements Iterator<Base> {
+ private int where;
+ private ArrayQueueIterator() {
+ where = (front + 1) % bases.length;
+ }
+ public boolean hasNext() {
+ return where != (rear + 1 ) % bases.length;
+ }
+ public Base next() {
+ if (hasNext()){
+ Base temp = bases[where];
+ where = (where + 1) % bases.length;
+ return temp;
+ } else {
+ throw new IllegalStateException("Queues at its end.");
+ }
+ }
+ public void remove() {
+ //Do nothing
+ }
+ }
+ public Iterator<Base> iterator() {
+ return new ArrayQueueIterator();
+ }
+}
+
+
+// QUEUETERATOR. Test ARRAY QUEUE's iterator. It's worth 20 points.
+
+class Queueterator {
+
+ // MAIN. Start execution here.
+
+ public static void main(String[] args) {
+
+ // Make an ARRAY QUEUE and enqueue some STRINGs. It can hold at most three.
+
+ ArrayQueue<String> queue = new ArrayQueue<String>(4);
+
+ queue.enqueue("A");
+ queue.enqueue("B");
+ queue.enqueue("C");
+
+ // Make a FIRST iterator for QUEUE and use it to visit QUEUE's elements.
+
+ Iterator<String> first = queue.iterator();
+ while (first.hasNext()) {
+ System.out.println(first.next()); // A B C one per line 5 pts.
+ }
+
+ // Make sure FIRST hasn't changed QUEUE.
+
+ System.out.println(queue.isEmpty()); // false 1 pt.
+ System.out.println(queue.dequeue()); // A 1 pt.
+ System.out.println(queue.dequeue()); // B 1 pt.
+ System.out.println(queue.dequeue()); // C 1 pt.
+ System.out.println(queue.isEmpty()); // true 1 pt.
+
+ // Let's enqueue more three more things to QUEUE.
+
+ queue.enqueue("X");
+ queue.enqueue("Y");
+ queue.enqueue("Z");
+
+ // Now make a SECOND iterator for QUEUE. The FIRST one does not work any more,
+ // because QUEUE has changed. Use SECOND to visit QUEUE's new elements.
+
+ Iterator<String> second = queue.iterator();
+ while (second.hasNext()) {
+ System.out.println(second.next()); // X Y Z one per line 5 pts.
+ }
+
+ // The new iterator hasn't changed QUEUE either.
+
+ System.out.println(queue.isEmpty()); // false 1 pt.
+ System.out.println(queue.dequeue()); // X 1 pt.
+ System.out.println(queue.dequeue()); // Y 1 pt.
+ System.out.println(queue.dequeue()); // Z 1 pt.
+ System.out.println(queue.isEmpty()); // true 1 pt.
+ }
+} \ No newline at end of file