priority queue

Java/PriorityLinked.java

@@ -0,0 +1,126 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package prioritylinked;
+
+/**
+ *
+ * @author RASHMI
+ */
+public class PriorityLinked {
+
+    /**
+     * @param args the command line arguments
+     */
+    public static void main(String[] args) {
+        // TODO code application logic here
+        PriorityQue x = new PriorityQue();
+        x.Insert(2);
+        x.Insert(1);
+        x.Insert(8);
+        x.Insert(4);
+        x.Insert(3);
+        x.removeFront();
+        x.display();
+
+    }
+
+}
+
+class Node {
+
+    int data;
+    Node next;
+    Node previous;
+
+    public Node(int data) {
+        this.data = data;
+        this.next = null;
+        this.previous = null;
+
+    }
+
+    void displayNode() {
+        System.out.println(this.data + " ");
+    }
+
+}
+
+class PriorityQue {
+
+    Node front, rear;
+
+    public PriorityQue() {
+        this.front = null;
+        this.rear = null;
+    }
+
+    void Insert(int value) {
+        Node node = new Node(value);
+        if (front == null) {
+            this.front = node;
+            this.rear = node;
+
+            return;
+        }
+        Node temp = front;
+        Node parent = null;
+
+        while (temp != null && temp.data <= value) {
+            parent = temp;
+            temp = temp.next;
+        }
+
+        if (parent == null) {
+
+            node.next = front;
+            front.previous = node;
+            front = node;
+        } else if (temp == null) {
+
+            parent.next = node;
+            node.previous = parent;
+        } else {
+
+            parent.next = node;
+            node.previous = parent;
+            node.next = temp;
+            temp.previous = node;
+        }
+
+    }
+    public Node removeFront() {
+        Node temp = front;
+
+        if (front != null) { // list might be empty
+            if (front.next == null) {
+
+                front = null;
+            } else {
+                front.next.previous = null;
+                front = front.next;
+            }
+        }
+        return temp;
+
+    }
+
+    public void display() {
+        Node current = front;
+
+        if (front == null) {
+            System.out.println("List is empty cannot display");
+            return;
+        }
+
+        while (current != null) {
+
+            System.out.print(current.data + " ");
+            current = current.next;
+        }
+        System.out.println("");
+    }
+
+}