From 7ea76784d8ac62abb7b01f6d982ece13e024285b Mon Sep 17 00:00:00 2001
From: KyleScharnhorst <scharkr1@uw.edu>
Date: Sat, 7 Oct 2017 20:40:48 -0700
Subject: [PATCH] Add: generic queue implementation.

Uses an arraylist its underlying datastructure.
---
 .../Queues/GenericArrayListQueue.java         | 42 +++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 data_structures/Queues/GenericArrayListQueue.java

diff --git a/data_structures/Queues/GenericArrayListQueue.java b/data_structures/Queues/GenericArrayListQueue.java
new file mode 100644
index 000000000000..0d35227f0ad1
--- /dev/null
+++ b/data_structures/Queues/GenericArrayListQueue.java
@@ -0,0 +1,42 @@
+import java.util.ArrayList;
+
+public class GenericArrayListQueue<T> {
+    ArrayList<T> _queue = new ArrayList<T>();
+
+    private boolean hasElements() {
+        return !_queue.isEmpty();
+    }
+
+    public T peek() {
+        T result = null;
+        if(this.hasElements()) { result = _queue.get(0); }
+        return result;
+    }
+
+    public boolean add(T element) {
+        return _queue.add(element);
+    }
+
+    public T poll() {
+        T result = null;
+        if(this.hasElements()) { result = _queue.remove(0); }
+        return result;
+    }
+
+    public static void main(String[] args) {
+        GenericArrayListQueue<Integer> queue = new GenericArrayListQueue<Integer>();
+        System.out.println("Running...");
+        assert queue.peek() == null;
+        assert queue.poll() == null;
+        assert queue.add(1) == true;
+        assert queue.peek() == 1;
+        assert queue.add(2) == true;
+        assert queue.peek() == 1;
+        assert queue.poll() == 1;
+        assert queue.peek() == 2;
+        assert queue.poll() == 2;
+        assert queue.peek() == null;
+        assert queue.poll() == null;
+        System.out.println("Finished.");
+    }
+}