feat: add PriorityQueueDemo1 demonstrating custom Comparator-based max-heap PriorityQueue

Implemented PriorityQueueDemo1.java to illustrate how PriorityQueue behavior can be
customized using a user-defined Comparator. Demonstrates descending order (max-heap)
prioritization with peek(), poll(), and iteration, showing element order before and
after deletion.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section 25 Collections Frameworks/Queue Interface/Priority Queue/src/PriorityQueueDemo1.java

@@ -1,7 +1,7 @@
 import java.util.Comparator;
 import java.util.PriorityQueue;
 
-class MyComp implements Comparator<Integer>
+class MyComp2 implements Comparator<Integer>
 {
     public int compare(Integer o1,Integer o2){
         if(o1<o2)return 1;
@@ -15,7 +15,6 @@ public static void main(String[] args) {
 
         PriorityQueue<Integer> PQ = new PriorityQueue<>(new MyComp());
 
-
         PQ.add(20);
         PQ.add(10);
         PQ.add(30);
@@ -33,4 +32,4 @@ public static void main(String[] args) {
 
         PQ.forEach((x)-> System.out.print(" "+x));
     }
-}
+}