[Manan] ADD:Task Scheduler using a Circular Linked List

Author: mananguptamg

TaskScheduler.java

@@ -0,0 +1,153 @@
+import java.util.Date;
+
+class TaskScheduler {
+    private class Node {
+        int taskId;
+        String taskName;
+        int priority;
+        Date dueDate;
+        Node next;
+
+        Node(int taskId, String taskName, int priority, Date dueDate) {
+            this.taskId = taskId;
+            this.taskName = taskName;
+            this.priority = priority;
+            this.dueDate = dueDate;
+            this.next = null;
+        }
+    }
+
+    private Node head = null;
+    private Node tail = null;
+    private Node currentTask = null;
+
+    public void addTaskAtEnd(int taskId, String taskName, int priority, Date dueDate) {
+        Node newNode = new Node(taskId, taskName, priority, dueDate);
+        if (head == null) {
+            head = newNode;
+            tail = newNode;
+            newNode.next = head;
+        } else {
+            tail.next = newNode;
+            tail = newNode;
+            tail.next = head;
+        }
+    }
+
+    public void addTaskAtBeginning(int taskId, String taskName, int priority, Date dueDate) {
+        Node newNode = new Node(taskId, taskName, priority, dueDate);
+        if (head == null) {
+            head = newNode;
+            tail = newNode;
+            newNode.next = head;
+        } else {
+            newNode.next = head;
+            head = newNode;
+            tail.next = head;
+        }
+    }
+
+    public void addTaskAtPosition(int taskId, String taskName, int priority, Date dueDate, int position) {
+        if (position <= 1) {
+            addTaskAtBeginning(taskId, taskName, priority, dueDate);
+            return;
+        }
+        Node newNode = new Node(taskId, taskName, priority, dueDate);
+        Node temp = head;
+        for (int i = 1; i < position - 1 && temp.next != head; i++) {
+            temp = temp.next;
+        }
+        newNode.next = temp.next;
+        temp.next = newNode;
+        if (temp == tail) {
+            tail = newNode;
+        }
+    }
+
+    public void removeTaskById(int taskId) {
+        if (head == null) return;
+        if (head.taskId == taskId) {
+            if (head == tail) {
+                head = null;
+                tail = null;
+            } else {
+                head = head.next;
+                tail.next = head;
+            }
+            return;
+        }
+        Node temp = head;
+        do {
+            if (temp.next.taskId == taskId) {
+                temp.next = temp.next.next;
+                if (temp.next == head) {
+                    tail = temp;
+                }
+                return;
+            }
+            temp = temp.next;
+        } while (temp != head);
+    }
+
+    public void viewCurrentTask() {
+        if (currentTask == null) {
+            currentTask = head;
+        }
+        if (currentTask != null) {
+            System.out.println("Current Task: " + currentTask.taskName + ", Priority: " + currentTask.priority);
+            currentTask = currentTask.next;
+        }
+    }
+
+    public void displayAllTasks() {
+        if (head == null) {
+            System.out.println("No tasks available.");
+            return;
+        }
+        Node temp = head;
+        do {
+            System.out.println("Task ID: " + temp.taskId + ", Name: " + temp.taskName + ", Priority: " + temp.priority);
+            temp = temp.next;
+        } while (temp != head);
+    }
+
+    public void searchByPriority(int priority) {
+        if (head == null) {
+            System.out.println("No tasks available.");
+            return;
+        }
+        Node temp = head;
+        boolean found = false;
+        do {
+            if (temp.priority == priority) {
+                System.out.println("Task Found - ID: " + temp.taskId + ", Name: " + temp.taskName);
+                found = true;
+            }
+            temp = temp.next;
+        } while (temp != head);
+        if (!found) {
+            System.out.println("No task with priority " + priority + " found.");
+        }
+    }
+
+    public static void main(String[] args) {
+        TaskScheduler scheduler = new TaskScheduler();
+        scheduler.addTaskAtEnd(1, "Task A", 3, new Date());
+        scheduler.addTaskAtEnd(2, "Task B", 2, new Date());
+        scheduler.addTaskAtBeginning(3, "Task C", 1, new Date());
+        scheduler.displayAllTasks();
+        scheduler.viewCurrentTask();
+        scheduler.searchByPriority(2);
+        scheduler.removeTaskById(2);
+        scheduler.displayAllTasks();
+    }
+}
+
+//SampleOutput
+//Task ID: 3, Name: Task C, Priority: 1
+//Task ID: 1, Name: Task A, Priority: 3
+//Task ID: 2, Name: Task B, Priority: 2
+//Current Task: Task C, Priority: 1
+//Task Found - ID: 2, Name: Task B
+//Task ID: 3, Name: Task C, Priority: 1
+//Task ID: 1, Name: Task A, Priority: 3