Update directory

Author: Hardvan

DIRECTORY.md

@@ -197,6 +197,7 @@
               * [PriorityQueues](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/queues/PriorityQueues.java)
               * [Queue](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/queues/Queue.java)
               * [QueueByTwoStacks](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/queues/QueueByTwoStacks.java)
+              * [SlidingWindowMaximum](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/queues/SlidingWindowMaximum.java)
             * stacks
               * [NodeStack](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/stacks/NodeStack.java)
               * [ReverseStack](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/stacks/ReverseStack.java)
@@ -819,6 +820,7 @@
               * [PriorityQueuesTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/queues/PriorityQueuesTest.java)
               * [QueueByTwoStacksTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/queues/QueueByTwoStacksTest.java)
               * [QueueTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/queues/QueueTest.java)
+              * [SlidingWindowMaximumTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/queues/SlidingWindowMaximumTest.java)
             * stacks
               * [LinkedListStackTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/stacks/LinkedListStackTest.java)
               * [StackArrayListTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/stacks/StackArrayListTest.java)