style: enable TypeName (#5214)

* style: enable `TypeName` in checkstyle

* style: enable `TypeName` in checkstyle

* Update directory

* style: use proper formatting

---------

Co-authored-by: StarDxxx <StarDxxx@users.noreply.github.com>
Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com>

src/main/java/com/thealgorithms/datastructures/graphs/AStar.java

@@ -9,8 +9,8 @@ import java.util.Comparator;
 import java.util.List;
 import java.util.PriorityQueue;
 
-public final class A_Star {
-    private A_Star() {
+public final class AStar {
+    private AStar() {
     }
 
     private static class Graph {

src/main/java/com/thealgorithms/datastructures/graphs/DIJSKSTRAS_ALGORITHM.java

@@ -4,7 +4,7 @@ for better understanding
  */
 package com.thealgorithms.datastructures.graphs;
 
-class dijkstras {
+class Dijkstras {
 
     int k = 9;
 
@@ -67,7 +67,7 @@ class dijkstras {
             {8, 11, 0, 0, 0, 0, 1, 0, 7},
             {0, 0, 2, 0, 0, 0, 6, 7, 0},
         };
-        dijkstras t = new dijkstras();
+        Dijkstras t = new Dijkstras();
         t.dijkstra(graph, 0);
     } // main
 } // djikstras

src/main/java/com/thealgorithms/datastructures/lists/MergeKSortedLinkedlist.java

@@ -7,7 +7,7 @@ import java.util.PriorityQueue;
 /**
  * @author Arun Pandey (https://github.com/pandeyarun709)
  */
-public class Merge_K_SortedLinkedlist {
+public class MergeKSortedLinkedlist {
 
     /**
      * This function merge K sorted LinkedList

src/main/java/com/thealgorithms/datastructures/lists/README.md

@@ -27,6 +27,6 @@ The `next` variable points to the next node in the data structure and value stor
 3. `CountSinglyLinkedListRecursion.java`: Recursively counts the size of a list.
 4. `CreateAndDetectLoop.java` : Create and detect a loop in a linked list.
 5. `DoublyLinkedList.java` : A modification of singly linked list which has a `prev` pointer to point to the previous node.
-6. `Merge_K_SortedLinkedlist.java` : Merges K sorted linked list with mergesort (mergesort is also the most efficient sorting algorithm for linked list).
+6. `MergeKSortedLinkedlist.java` : Merges K sorted linked list with mergesort (mergesort is also the most efficient sorting algorithm for linked list).
 7. `RandomNode.java` : Selects a random node from given linked list and diplays it.
 8. `SkipList.java` : Data Structure used for storing a sorted list of elements with help of a Linked list hierarchy that connects to subsequences of elements.