package com.vzt.Test.PQ;
public class PQUsingDLL {
public static void main(String[] vj) {
PriorityQUsingDLL obj = new PriorityQUsingDLL();
System.out.println("INSERTING...");
obj.enqueue(2, 3);
obj.enqueue(3, 4);
obj.enqueue(4, 5);
obj.enqueue(5, 2);
obj.enqueue(6, 7);
obj.enqueue(1, 1);
obj.displayQ();
System.out.println("REMOVING...");
obj.dequeue();
obj.dequeue();
obj.displayQ();
}
}
class PriorityQUsingDLL {
private DoublyLinkList list;
public PriorityQUsingDLL() {
list = new DoublyLinkList();
}
public void enqueue(int x, int p) {
list.insert(x, p);
}
public void dequeue() {
list.remove();
}
public void displayQ() {
System.out.println("PRINTING...");
list.display();
}
}
class DoublyLinkList {
private Node first = null;
private Node last = null;
public DoublyLinkList() {
first = null;
last = null;
}
public boolean isEmpty() {
return (first == null);
}
public void insert(int n, int p) {
Node newNode = new Node(n, p);
if (first == null) {
first = newNode;
last = newNode;
} else {
if (p <= first.priority) {
newNode.next = first;
first.prev = newNode.next;
first = newNode;
}
else if (p > last.priority) {
last.next = newNode;
newNode.prev = last.next;
last = newNode;
}
else {
Node start = first.next;
while (start.priority > p)
start = start.next;
start.prev.next = newNode;
newNode.next = start.prev;
newNode.prev = start.prev.next;
start.prev = newNode.next;
}
}
}
public Node remove() {
if (first == null) {
last = null;
return null;
}
Node temp = first;
first = first.next;
temp.displayNode();
return temp;
}
public void display() {
Node current = first;
while (current != null) {
current.displayNode();
current = current.next;
}
System.out.println(" ");
}
public int peek() {
return first.info;
}
}
class Node {
int info;
int priority;
Node prev, next;
Node(int x, int p) {
info = x;
priority = p;
prev = null;
next = null;
}
public void displayNode() {
System.out.println("Data = " + info);
}
}
