Add JobSchedulingWithDeadline algorithm (#5608)

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};
+    }
+}