checked with coding style issues

Author: Darshan-Baligeri

src/main/java/com/thealgorithms/shufflealogrithm/ConstrainedShuffle.java

@@ -6,6 +6,10 @@
 
 public class ConstrainedShuffle {
 
+    private ConstrainedShuffle() {
+        // Prevent instantiation
+    }
+
     /**
      * Shuffles the array so that no element stays in its original position.
      *

src/main/java/com/thealgorithms/shufflealogrithm/GroupShuffle.java

@@ -6,6 +6,10 @@
 
 public class GroupShuffle {
 
+    private GroupShuffle() {
+        // Prevent instantiation
+    }
+
     /**
      * Divides the array into k equal-sized groups and shuffles each group separately.
      * Returns an empty list if the group count exceeds the array length.

src/main/java/com/thealgorithms/shufflealogrithm/ShuffleByRange.java

@@ -4,6 +4,10 @@
 
 public class ShuffleByRange {
 
+    private ShuffleByRange() {
+        // Prevent instantiation
+    }
+
     /**
      * Shuffles elements within a specified index range, leaving elements outside this range unchanged.
      *

src/main/java/com/thealgorithms/shufflealogrithm/UnderstandingShuffleAlgo.java

@@ -4,6 +4,10 @@
 
 public class UnderstandingShuffleAlgo {
 
+    private UnderstandingShuffleAlgo() {
+        // Prevent instantiation
+    }
+
     /**
      * Shuffles the elements in the array randomly.
      * Uses a method that gives each item an equal chance to appear in any position.

src/main/java/com/thealgorithms/shufflealogrithm/UniquePairShuffle.java

@@ -6,6 +6,10 @@
 
 public class UniquePairShuffle {
 
+    private UniquePairShuffle() {
+        // Prevent instantiation
+    }
+
     /**
      * Pairs each element in the array with another element randomly, ensuring no pair repeats.
      * If the array length is odd, pairing cannot be completed, so an empty list is returned.
@@ -17,7 +21,9 @@ public static List<int[]> pairShuffle(int[] array) {
         List<int[]> pairs = new ArrayList<>();
 
         // Handle edge case: If the array length is odd, pairing is not possible
-        if (array.length % 2 != 0) return pairs;
+        if (array.length % 2 != 0) {
+            return pairs;
+        }
 
         List<Integer> shuffledList = new ArrayList<>();
         for (int num : array) {

src/main/java/com/thealgorithms/shufflealogrithm/WeightedShuffle.java

@@ -5,6 +5,10 @@
 
 public class WeightedShuffle {
 
+    private WeightedShuffle() {
+        // Prevent instantiation
+    }
+
     /**
      * Shuffles elements based on their weights. Higher weight elements are more likely to appear earlier.
      *
@@ -13,7 +17,9 @@ public class WeightedShuffle {
      */
     public static void weightedShuffle(int[] array, int[] weights) {
         // Edge case: Check if weights match the array size
-        if (array == null || weights == null || array.length != weights.length) return;
+        if (array == null || weights == null || array.length != weights.length) {
+            return;
+        }
 
         Integer[] indices = new Integer[array.length];
         for (int i = 0; i < array.length; i++) {