style: Apply Java code style guidelines

Author: Siddhram

src/main/java/com/thealgorithms/graph/DisjointSet.java

@@ -1,6 +1,7 @@
 package com.thealgorithms.graph;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Implementation of the Disjoint Set (Union-Find) data structure with path

src/main/java/com/thealgorithms/graph/TopologicalSort.java

@@ -1,6 +1,10 @@
 package com.thealgorithms.graph;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
 
 /**
  * Implementation of Kahn's algorithm for topological sorting of a directed

src/test/java/com/thealgorithms/graph/DisjointSetTest.java

@@ -1,6 +1,9 @@
 package com.thealgorithms.graph;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.List;
 import org.junit.jupiter.api.DisplayName;

src/test/java/com/thealgorithms/graph/TopologicalSortTest.java

@@ -1,6 +1,10 @@
 package com.thealgorithms.graph;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.Arrays;
 import java.util.List;