Added PriorityQueueSort.java

Implemented PriorityQueueSort using Java's PriorityQueue (Min-Heap).
- Returns the array sorted in ascending order
- Time complexity: O(n log n)
- Space complexity: O(n)

Author: Rahul-150705

src/main/java/com/thealgorithms/sorts/PriorityQueueSort.java

@@ -0,0 +1,44 @@
+package com.thealgorithms.sorts;
+
+import java.util.PriorityQueue;
+
+/**
+ * Sorts an array using Java's PriorityQueue (Min-Heap).
+ *
+ * <p>Example:
+ * Input: [7, 2, 9, 4, 1]
+ * Output: [1, 2, 4, 7, 9]
+ *
+ * <p>Time Complexity:
+ * - Inserting n elements into the PriorityQueue → O(n log n)
+ * - Polling n elements → O(n log n)
+ * - Total: O(n log n)
+ *
+ * Space Complexity: O(n) for the PriorityQueue
+ */
+public class PriorityQueueSort {
+
+    /**
+     * Sorts the given array in ascending order using a PriorityQueue.
+     *
+     * @param arr the array to be sorted
+     * @return the sorted array (in-place)
+     */
+    public static int[] sort(int[] arr) {
+        if (arr == null || arr.length == 0) {
+            return arr;
+        }
+
+        PriorityQueue<Integer> pq = new PriorityQueue<>();
+        for (int num : arr) {
+            pq.offer(num);
+        }
+
+        int i = 0;
+        while (!pq.isEmpty()) {
+            arr[i++] = pq.poll();
+        }
+
+        return arr;
+    }
+}