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-rw-r--r--labs/lab10_tree/SimpleQueue.java72
1 files changed, 72 insertions, 0 deletions
diff --git a/labs/lab10_tree/SimpleQueue.java b/labs/lab10_tree/SimpleQueue.java
new file mode 100644
index 0000000..64d7c11
--- /dev/null
+++ b/labs/lab10_tree/SimpleQueue.java
@@ -0,0 +1,72 @@
+
+public class SimpleQueue<T>
+{
+ private Node firstNode;
+ private Node lastNode;
+
+ public SimpleQueue()
+ {
+ firstNode = null;
+ lastNode = null;
+ }
+
+ public void enqueue(T newEntry)
+ {
+ Node newNode = new Node(newEntry);
+
+ if(firstNode == null)
+ {
+ firstNode = newNode;
+ lastNode = newNode;
+ }
+ else
+ {
+ lastNode.next = newNode;
+ lastNode = newNode;
+ }
+ }
+
+ public T dequeue()
+ {
+ T result = null;
+
+ if(firstNode != null)
+ {
+ result = firstNode.data;
+ if(lastNode == firstNode)
+ {
+ lastNode = null;
+ }
+ firstNode = firstNode.next;
+ }
+
+ return result;
+ }
+
+ public T getFront()
+ {
+ if(firstNode != null)
+ {
+ return firstNode.data;
+ }
+
+ return null;
+ }
+
+ private class Node
+ {
+ private T data;
+ private Node next;
+
+ public Node(T aData, Node nextNode)
+ {
+ data = aData;
+ next = nextNode;
+ }
+
+ public Node(T aData)
+ {
+ this(aData, null);
+ }
+ }
+}