diff --git a/DIRECTORY.md b/DIRECTORY.md index af1e4f284445..a2f65834b498 100644 --- a/DIRECTORY.md +++ b/DIRECTORY.md @@ -475,6 +475,7 @@ * scheduling * [FCFSScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/FCFSScheduling.java) * [HighestResponseRatioNextScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/HighestResponseRatioNextScheduling.java) + * [JobSchedulingWithDeadline](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/JobSchedulingWithDeadline.java) * [MLFQScheduler](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/MLFQScheduler.java) * [PreemptivePriorityScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/PreemptivePriorityScheduling.java) * [RRScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/RRScheduling.java) @@ -963,6 +964,7 @@ * scheduling * [FCFSSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/FCFSSchedulingTest.java) * [HighestResponseRatioNextSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/HighestResponseRatioNextSchedulingTest.java) + * [JobSchedulingWithDeadlineTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/JobSchedulingWithDeadlineTest.java) * [MLFQSchedulerTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/MLFQSchedulerTest.java) * [PreemptivePrioritySchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/PreemptivePrioritySchedulingTest.java) * [RRSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/RRSchedulingTest.java) diff --git a/src/main/java/com/thealgorithms/scheduling/JobSchedulingWithDeadline.java b/src/main/java/com/thealgorithms/scheduling/JobSchedulingWithDeadline.java new file mode 100644 index 000000000000..49638d39fc2a --- /dev/null +++ b/src/main/java/com/thealgorithms/scheduling/JobSchedulingWithDeadline.java @@ -0,0 +1,88 @@ +package com.thealgorithms.scheduling; + +import java.util.Arrays; +import java.util.Comparator; + +/** + * A class that implements a job scheduling algorithm to maximize profit + * while adhering to job deadlines and arrival times. + * + * This class provides functionality to schedule jobs based on their profit, + * arrival time, and deadlines to ensure that the maximum number of jobs is completed + * within the given timeframe. It sorts the jobs in decreasing order of profit + * and attempts to assign them to the latest possible time slots. + */ +public final class JobSchedulingWithDeadline { + private JobSchedulingWithDeadline() { + } + + /** + * Represents a job with an ID, arrival time, deadline, and profit. + * + * Each job has a unique identifier, an arrival time (when it becomes available for scheduling), + * a deadline by which it must be completed, and a profit associated with completing the job. + */ + static class Job { + int jobId; + int arrivalTime; + int deadline; + int profit; + + /** + * Constructs a Job instance with the specified job ID, arrival time, deadline, and profit. + * + * @param jobId Unique identifier for the job + * @param arrivalTime Time when the job becomes available for scheduling + * @param deadline Deadline for completing the job + * @param profit Profit earned upon completing the job + */ + Job(int jobId, int arrivalTime, int deadline, int profit) { + this.jobId = jobId; + this.arrivalTime = arrivalTime; + this.deadline = deadline; + this.profit = profit; + } + } + + /** + * Schedules jobs to maximize profit while respecting their deadlines and arrival times. + * + * This method sorts the jobs in descending order of profit and attempts + * to allocate them to time slots that are before or on their deadlines, + * provided they have arrived. The function returns an array where the first element + * is the total number of jobs scheduled and the second element is the total profit earned. + * + * @param jobs An array of Job objects, each representing a job with an ID, arrival time, + * deadline, and profit. + * @return An array of two integers: the first element is the count of jobs + * that were successfully scheduled, and the second element is the + * total profit earned from those jobs. + */ + public static int[] jobSequencingWithDeadlines(Job[] jobs) { + Arrays.sort(jobs, Comparator.comparingInt(job -> - job.profit)); + + int maxDeadline = Arrays.stream(jobs).mapToInt(job -> job.deadline).max().orElse(0); + + int[] timeSlots = new int[maxDeadline]; + Arrays.fill(timeSlots, -1); + + int count = 0; + int maxProfit = 0; + + // Schedule the jobs + for (Job job : jobs) { + if (job.arrivalTime <= job.deadline) { + for (int i = Math.min(job.deadline - 1, maxDeadline - 1); i >= job.arrivalTime - 1; i--) { + if (timeSlots[i] == -1) { + timeSlots[i] = job.jobId; + count++; + maxProfit += job.profit; + break; + } + } + } + } + + return new int[] {count, maxProfit}; + } +} diff --git a/src/test/java/com/thealgorithms/scheduling/JobSchedulingWithDeadlineTest.java b/src/test/java/com/thealgorithms/scheduling/JobSchedulingWithDeadlineTest.java new file mode 100644 index 000000000000..538db92a1f26 --- /dev/null +++ b/src/test/java/com/thealgorithms/scheduling/JobSchedulingWithDeadlineTest.java @@ -0,0 +1,43 @@ +package com.thealgorithms.scheduling; + +import static org.junit.jupiter.api.Assertions.assertArrayEquals; + +import org.junit.jupiter.api.Test; + +class JobSchedulingWithDeadlineTest { + + @Test + void testJobSequencingWithDeadlines1() { + JobSchedulingWithDeadline.Job[] jobs = {new JobSchedulingWithDeadline.Job(1, 1, 4, 20), new JobSchedulingWithDeadline.Job(2, 1, 1, 10), new JobSchedulingWithDeadline.Job(3, 1, 1, 40), new JobSchedulingWithDeadline.Job(4, 1, 1, 30)}; + int[] result = JobSchedulingWithDeadline.jobSequencingWithDeadlines(jobs); + assertArrayEquals(new int[] {2, 60}, result); // Expected output: 2 jobs, 60 profit + } + + @Test + void testJobSequencingWithDeadlines2() { + JobSchedulingWithDeadline.Job[] jobs = {new JobSchedulingWithDeadline.Job(1, 1, 2, 100), new JobSchedulingWithDeadline.Job(2, 1, 1, 19), new JobSchedulingWithDeadline.Job(3, 1, 2, 27), new JobSchedulingWithDeadline.Job(4, 1, 1, 25), new JobSchedulingWithDeadline.Job(5, 1, 1, 15)}; + int[] result = JobSchedulingWithDeadline.jobSequencingWithDeadlines(jobs); + assertArrayEquals(new int[] {2, 127}, result); // Expected output: 2 jobs, 127 profit + } + + @Test + void testJobSequencingWithDeadlinesWithArrivalTimes() { + JobSchedulingWithDeadline.Job[] jobs = {new JobSchedulingWithDeadline.Job(1, 2, 5, 50), new JobSchedulingWithDeadline.Job(2, 3, 4, 60), new JobSchedulingWithDeadline.Job(3, 1, 3, 20)}; + int[] result = JobSchedulingWithDeadline.jobSequencingWithDeadlines(jobs); + assertArrayEquals(new int[] {3, 130}, result); // All 3 jobs fit within their deadlines + } + + @Test + void testJobSequencingWithDeadlinesNoJobs() { + JobSchedulingWithDeadline.Job[] jobs = {}; + int[] result = JobSchedulingWithDeadline.jobSequencingWithDeadlines(jobs); + assertArrayEquals(new int[] {0, 0}, result); // No jobs, 0 profit + } + + @Test + void testJobSequencingWithDeadlinesSingleJob() { + JobSchedulingWithDeadline.Job[] jobs = {new JobSchedulingWithDeadline.Job(1, 1, 1, 50)}; + int[] result = JobSchedulingWithDeadline.jobSequencingWithDeadlines(jobs); + assertArrayEquals(new int[] {1, 50}, result); // 1 job scheduled, 50 profit + } +}