Create PriorityQueueApp.java

PriorityQueueApp.java

@@ -0,0 +1,126 @@
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class PriorityQueueApp {
+
+    public static void main(String[] args) {
+
+        PriorityQueue x = new PriorityQueue();
+        x.enqueue("Lak", 2.63);
+        x.enqueue("Sam", 3.5);
+        x.enqueue("Mursit", 1.2);
+        x.enqueue("Ran", 4.9);
+        x.enqueue("Dock", 1.2);
+        x.enqueue("Anan", 0.98);
+        x.enqueue("Yello", 2);
+
+        x.display();
+
+        System.out.println();
+
+        try {
+            System.out.println(x.dequeue() + " ,student is removed from the list.");
+        } catch (Exception e) {
+            Logger.getLogger(PriorityQueueApp.class.getName()).log(Level.SEVERE, null, e);
+        }
+        System.out.println();
+        x.display();
+    }
+
+}
+
+class Student {
+
+    String studentName;
+    double gpa;
+
+    Student(String studentName, double gpa) {
+        //fill the body
+
+        this.studentName = studentName;
+        this.gpa = gpa;
+    }
+}
+
+class Node {
+
+    Student s;
+    Node next;
+
+    Node(Student s) {
+        this.s = s;
+        this.next = null;
+    }
+}
+
+class PriorityQueue {
+
+    private Node head;
+    private Node tail;
+
+    public PriorityQueue() {
+        this.head = null;
+        this.tail = null;
+    }
+
+    public void enqueue(String studentName, double gpa) {
+        if (head == null) {
+            Student student = new Student(studentName, gpa);
+            head = new Node(student);
+            tail = head;
+            return;
+        }
+
+        Student student = new Student(studentName, gpa);
+        head = insertNewNode(student, head);
+    }
+
+    private Node insertNewNode(Student student, Node currentNode) {
+        //class to inser new node
+
+        if (student.gpa < currentNode.s.gpa) {
+            Node newNode = new Node(student);
+            newNode.next = currentNode;
+            return newNode;
+        }
+
+        if (currentNode.next == null) {
+            currentNode.next = new Node(student);
+            this.tail = currentNode.next;
+        } else {
+            currentNode.next = insertNewNode(student, currentNode.next);
+        }
+
+        return currentNode;
+    }
+
+    public String dequeue() throws Exception {
+        /*remove the node of the front student and return the name of the student*/
+
+        if (this.head == null) {
+            throw new Exception("Queue is Empty");
+        }
+        String removedData = this.head.s.studentName;
+        this.head = this.head.next;
+        return removedData;
+    }
+
+    public String peek() throws Exception {
+        //return the name of the front student
+
+        return this.head.s.studentName;
+    }
+
+    public void display() {
+        //display all the student names in the queue
+
+        System.out.println("Studets list with GPA :");
+        Node currentNode = this.head;
+        while (currentNode != null) {
+            System.out.println(currentNode.s.gpa + "  -  " + currentNode.s.studentName);
+            currentNode = currentNode.next;
+        }
+    }
+
+}