Add SelfAdjustingScheduling algorithm (#5811)

Author: Hardvan

DIRECTORY.md

@@ -539,6 +539,7 @@
             * [NonPreemptivePriorityScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/NonPreemptivePriorityScheduling.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)
+            * [SelfAdjustingScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/SelfAdjustingScheduling.java)
             * [SJFScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/SJFScheduling.java)
             * [SlackTimeScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/SlackTimeScheduling.java)
             * [SRTFScheduling](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/scheduling/SRTFScheduling.java)
@@ -1136,6 +1137,7 @@
             * [NonPreemptivePrioritySchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/NonPreemptivePrioritySchedulingTest.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)
+            * [SelfAdjustingSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/SelfAdjustingSchedulingTest.java)
             * [SJFSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/SJFSchedulingTest.java)
             * [SlackTimeSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/SlackTimeSchedulingTest.java)
             * [SRTFSchedulingTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/scheduling/SRTFSchedulingTest.java)

src/main/java/com/thealgorithms/scheduling/SelfAdjustingScheduling.java

@@ -0,0 +1,63 @@
+package com.thealgorithms.scheduling;
+
+import java.util.PriorityQueue;
+
+/**
+ * SelfAdjustingScheduling is an algorithm where tasks dynamically adjust
+ * their priority based on real-time feedback, such as wait time and CPU usage.
+ * Tasks that wait longer will automatically increase their priority,
+ * allowing for better responsiveness and fairness in task handling.
+ *
+ * Use Case: Real-time systems that require dynamic prioritization
+ * of tasks to maintain system responsiveness and fairness.
+ *
+ * @author Hardvan
+ */
+public final class SelfAdjustingScheduling {
+
+    private static class Task implements Comparable<Task> {
+        String name;
+        int waitTime;
+        int priority;
+
+        Task(String name, int priority) {
+            this.name = name;
+            this.waitTime = 0;
+            this.priority = priority;
+        }
+
+        void incrementWaitTime() {
+            waitTime++;
+            priority = priority + waitTime;
+        }
+
+        @Override
+        public int compareTo(Task other) {
+            return Integer.compare(this.priority, other.priority);
+        }
+    }
+
+    private final PriorityQueue<Task> taskQueue;
+
+    public SelfAdjustingScheduling() {
+        taskQueue = new PriorityQueue<>();
+    }
+
+    public void addTask(String name, int priority) {
+        taskQueue.offer(new Task(name, priority));
+    }
+
+    public String scheduleNext() {
+        if (taskQueue.isEmpty()) {
+            return null;
+        }
+        Task nextTask = taskQueue.poll();
+        nextTask.incrementWaitTime();
+        taskQueue.offer(nextTask);
+        return nextTask.name;
+    }
+
+    public boolean isEmpty() {
+        return taskQueue.isEmpty();
+    }
+}

src/test/java/com/thealgorithms/scheduling/SelfAdjustingSchedulingTest.java

@@ -0,0 +1,57 @@
+package com.thealgorithms.scheduling;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class SelfAdjustingSchedulingTest {
+
+    private SelfAdjustingScheduling scheduler;
+
+    @BeforeEach
+    public void setup() {
+        scheduler = new SelfAdjustingScheduling();
+    }
+
+    @Test
+    public void testAddAndScheduleSingleTask() {
+        scheduler.addTask("Task1", 5);
+        assertEquals("Task1", scheduler.scheduleNext());
+    }
+
+    @Test
+    public void testAddMultipleTasks() {
+        scheduler.addTask("Task1", 5);
+        scheduler.addTask("Task2", 1);
+        scheduler.addTask("Task3", 3);
+        assertEquals("Task2", scheduler.scheduleNext());
+        assertEquals("Task2", scheduler.scheduleNext());
+        assertEquals("Task3", scheduler.scheduleNext());
+    }
+
+    @Test
+    public void testPriorityAdjustment() {
+        scheduler.addTask("Task1", 1);
+        scheduler.addTask("Task2", 1);
+        scheduler.scheduleNext();
+        scheduler.scheduleNext();
+        scheduler.scheduleNext();
+        assertEquals("Task2", scheduler.scheduleNext());
+    }
+
+    @Test
+    public void testEmptyScheduler() {
+        assertNull(scheduler.scheduleNext());
+    }
+
+    @Test
+    public void testTaskReschedulingAfterWait() {
+        scheduler.addTask("Task1", 1);
+        scheduler.addTask("Task2", 2);
+        scheduler.scheduleNext();
+        scheduler.scheduleNext();
+        assertEquals("Task1", scheduler.scheduleNext());
+    }
+}