diff --git a/DIRECTORY.md b/DIRECTORY.md index b7707a254ab6..bad138b341e1 100644 --- a/DIRECTORY.md +++ b/DIRECTORY.md @@ -207,6 +207,7 @@ * [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) * [TokenBucket](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/queues/TokenBucket.java) * stacks * [NodeStack](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/datastructures/stacks/NodeStack.java) @@ -882,6 +883,7 @@ * [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) * [TokenBucketTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/queues/TokenBucketTest.java) * stacks * [NodeStackTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/stacks/NodeStackTest.java) diff --git a/src/main/java/com/thealgorithms/datastructures/queues/SlidingWindowMaximum.java b/src/main/java/com/thealgorithms/datastructures/queues/SlidingWindowMaximum.java new file mode 100644 index 000000000000..d6720dd01e29 --- /dev/null +++ b/src/main/java/com/thealgorithms/datastructures/queues/SlidingWindowMaximum.java @@ -0,0 +1,63 @@ +package com.thealgorithms.datastructures.queues; + +import java.util.Deque; +import java.util.LinkedList; + +/** + * The {@code SlidingWindowMaximum} class provides a method to efficiently compute + * the maximum element within every sliding window of size {@code k} in a given array. + * + *
The algorithm uses a deque to maintain the indices of useful elements within + * the current sliding window. The time complexity of this approach is O(n) since + * each element is processed at most twice. + * + * @author Hardvan + */ +public final class SlidingWindowMaximum { + private SlidingWindowMaximum() { + } + + /** + * Returns an array of the maximum values for each sliding window of size {@code k}. + *
If {@code nums} has fewer elements than {@code k}, the result will be an empty array. + *
Example: + *
+ * Input: nums = [1, 3, -1, -3, 5, 3, 6, 7], k = 3 + * Output: [3, 3, 5, 5, 6, 7] + *+ * + * @param nums the input array of integers + * @param k the size of the sliding window + * @return an array containing the maximum element for each sliding window + */ + public static int[] maxSlidingWindow(int[] nums, int k) { + int n = nums.length; + if (n < k || k == 0) { + return new int[0]; + } + + int[] result = new int[n - k + 1]; + Deque