feat: finish Lab3

Array.java

@@ -1,18 +1,18 @@
 /**
- * The Array<T> for CS2030S 
+ * The Array<T> for CS2030S
  *
  * @author Yadunand Prem
  * @version CS2030S AY21/22 Semester 2
  */
 
-class Array<T extends Comparable<T>> { 
+class Array<T extends Comparable<T>> {
   private T[] array;
 
   public Array(int size) {
-    // The only way to add values to `array` is via set(), and we can only put 
-    // objects of type T via that method. Thus, it is safe to cast Comparable[] 
+    // The only way to add values to `array` is via set(), and we can only put
+    // objects of type T via that method. Thus, it is safe to cast Comparable[]
     // to T[].
-    @SuppressWarnings({"unchecked", "rawtypes"})
+    @SuppressWarnings("unchecked")
     T[] temp = (T[]) new Comparable[size];
     this.array = temp;
   }
@@ -27,7 +27,7 @@ class Array<T extends Comparable<T>> {
 
   public T min() {
     T result = this.array[0];
-    for (T i: this.array) {
+    for (T i : this.array) {
       if (i.compareTo(result) < 0) {
         result = i;
       }
@@ -35,6 +35,10 @@ class Array<T extends Comparable<T>> {
     return result;
   }
 
+  public int length() {
+    return this.array.length;
+  }
+
   @Override
   public String toString() {
     StringBuilder s = new StringBuilder("[ ");

ArrivalEvent.java

@@ -22,16 +22,22 @@ class ArrivalEvent extends Event {
   @Override
   public Event[] simulate() {
     ServiceCounter availableCounter = this.shop.getAvailableCounter();
-    // check if counters are available. If none, push customer to queue if not full.
-    // If full, customer departs
-    if (availableCounter == null) {
-      if (this.shop.isQueueFull()) {
-        return new Event[] { new DepartureEvent(this.getTime(), customer, shop) };
-      }
-      return new Event[] { new JoinQueueEvent(customer, shop) };
+    // check if counters are available. If available, start service for that
+    // customer
+    if (availableCounter != null) {
+      return new Event[] {
+          new ServiceBeginEvent(this.getTime(), customer, shop, availableCounter) };
     }
-    return new Event[] {
-        new ServiceBeginEvent(this.getTime(), customer, shop, availableCounter) };
+    // if no counters available, check if queue slots avialable in counters
+    availableCounter = this.shop.findCounterWithQueue();
+    if (availableCounter != null) {
+      return new Event[] { new JoinCounterQueueEvent(this.getTime(), this.customer, this.shop, availableCounter) };
+    }
+    // if shop queue isn't empty, join shop queue
+    if (!this.shop.isQueueFull()) {
+      return new Event[] { new JoinShopQueueEvent(customer, shop) };
+    }
+    return new Event[] { new DepartureEvent(this.getTime(), customer, shop) };
 
   }
 

JoinCounterQueueEvent.java

@@ -0,0 +1,24 @@
+public class JoinCounterQueueEvent extends Event {
+  private Customer customer;
+  private Shop shop;
+  private ServiceCounter counter;
+
+  public JoinCounterQueueEvent(double time, Customer customer, Shop shop, ServiceCounter counter) {
+    super(time);
+    this.customer = customer;
+    this.shop = shop;
+  }
+
+  @Override
+  public Event[] simulate() {
+    this.counter.joinQueue(customer);
+    return new Event[] {};
+  }
+
+  @Override
+  public String toString() {
+    return String.format("%s: %s joined counter queue (at %s)",
+        super.toString(),
+        this.customer, this.counter);
+  }
+}

JoinShopQueueEvent.java

@@ -1,9 +1,9 @@
 
-class JoinQueueEvent extends Event {
+class JoinShopQueueEvent extends Event {
   private Customer customer;
   private Shop shop;
 
-  public JoinQueueEvent(Customer customer, Shop shop) {
+  public JoinShopQueueEvent(Customer customer, Shop shop) {
     super(customer.getArrivalTIme());
     this.customer = customer;
     this.shop = shop;
@@ -12,12 +12,12 @@ class JoinQueueEvent extends Event {
   @Override
   public Event[] simulate() {
     this.shop.joinQueue(customer);
-      return new Event[] {};
+    return new Event[] {};
   }
 
   @Override
   public String toString() {
-    return String.format("%s: %s joined queue %s",
+    return String.format("%s: %s joined shop queue %s",
         super.toString(),
         this.customer, this.shop.queueString());
   }

Queue.java

@@ -29,10 +29,10 @@ class Queue<T> {
    */
   public Queue(int size) {
     this.maxSize = size;
-    // The only way to add values to `items` is via enq(), and we can only put 
-    // objects of type T via that method. Thus, it is safe to cast Comparable[] 
+    // The only way to add values to `items` is via enq(), and we can only put
+    // objects of type T via that method. Thus, it is safe to cast Comparable[]
     // to T[].
-    @SuppressWarnings({"unchecked", "rawtypes"})
+    @SuppressWarnings("unchecked")
     T[] temp = (T[]) new Object[size];
     this.items = temp;
     this.first = -1;

ServiceCounter.java

@@ -24,6 +24,22 @@ public class ServiceCounter implements Comparable<ServiceCounter> {
     this.available = true;
   }
 
+  public boolean isQueueFull() {
+    return this.queue.isFull();
+  }
+
+  public boolean isQueueEmpty() {
+    return this.queue.isEmpty();
+  }
+
+  public void joinQueue(Customer customer) {
+    this.queue.enq(customer);
+  }
+
+  public Customer leaveQueue() {
+    return this.queue.deq();
+  }
+
   public ServiceCounter(int queueSize) {
     this.id = lastId++;
     this.available = true;
@@ -32,7 +48,7 @@ public class ServiceCounter implements Comparable<ServiceCounter> {
 
   @Override
   public String toString() {
-    return "S" + id;
+    return String.format("S%s %s", id, this.queue);
   }
 
   @Override

ServiceEndEvent.java

@@ -26,7 +26,33 @@ class ServiceEndEvent extends Event {
 
   @Override
   public Event[] simulate() {
+    // if there are customers in the counter queue, they will be serviced next.
+    // Customers in the shop queue will then be added to the counter queue
+    if (!this.counter.isQueueEmpty()) {
+      Customer serviceCustomer = this.counter.leaveQueue();
+
+      if (!this.shop.isQueueEmpty()) {
+        return new Event[] {
+            new DepartureEvent(this.getTime(), this.customer, this.shop, this.counter),
+            new ServiceBeginEvent(this.getTime(), serviceCustomer, this.shop, this.counter),
+            new JoinCounterQueueEvent(this.getTime(), this.shop.leaveQueue(), this.shop, counter)
+        };
+      }
+      return new Event[] {
+          new DepartureEvent(this.getTime(), this.customer, this.shop, this.counter),
+          new ServiceBeginEvent(this.getTime(), serviceCustomer, this.shop, this.counter),
+      };
+    }
+    // There can also be the case where the counter queue may be empty but there are
+    // customers in the shop queue.
+    if (!this.shop.isQueueEmpty()) {
+      return new Event[] {
+          new DepartureEvent(this.getTime(), this.customer, this.shop, this.counter),
+          new ServiceBeginEvent(this.getTime(), this.shop.leaveQueue(), this.shop, this.counter),
+      };
+    }
+    // else there are no more customers in the queue, and the counter can be freed
     this.counter.free();
-    return new Event[] { new DepartureEvent(this.getTime(), customer, shop, counter) };
+    return new Event[] { new DepartureEvent(this.getTime(), this.customer, this.shop, this.counter) };
   }
 }

Shop.java

@@ -26,20 +26,19 @@ public class Shop {
    */
 
   public ServiceCounter getAvailableCounter() {
-    // Check if this logic can be moved elsewhere
-    /*
-    for (int i = 0; i < this.counters.length; i++) {
-      if (this.counters[i].isAvailable()) {
-        return counters[i];
+    for (int i = 0; i < this.counters.length(); i++) {
+      ServiceCounter counter = this.counters.get(i);
+      if (counter.isAvailable()) {
+        return counter;
       }
     }
-    */
     return null;
   }
 
   public boolean isQueueFull() {
     return this.queue.isFull();
   }
+
   public boolean isQueueEmpty() {
     return this.queue.isEmpty();
   }
@@ -52,6 +51,14 @@ public class Shop {
     return this.queue.deq();
   }
 
+  public ServiceCounter findCounterWithQueue() {
+    ServiceCounter minCounter = this.counters.min();
+    if (!minCounter.isQueueFull()) {
+      return minCounter;
+    }
+    return null;
+  }
+
   public String queueString() {
     return this.queue.toString();
   }