style: enable MethodName in CheckStyle (#5182)

enabled: MethodName in CheckStyle

src/main/java/com/thealgorithms/datastructures/heaps/LeftistHeap.java

@@ -91,7 +91,7 @@ public class LeftistHeap {
     }
 
     // Returns and removes the minimum element in the heap
-    public int extract_min() {
+    public int extractMin() {
         // If is empty return -1
         if (isEmpty()) return -1;
 
@@ -101,17 +101,17 @@ public class LeftistHeap {
     }
 
     // Function returning a list of an in order traversal of the data structure
-    public ArrayList<Integer> in_order() {
+    public ArrayList<Integer> inOrder() {
         ArrayList<Integer> lst = new ArrayList<>();
-        in_order_aux(root, lst);
+        inOrderAux(root, lst);
         return new ArrayList<>(lst);
     }
 
     // Auxiliary function for in_order
-    private void in_order_aux(Node n, ArrayList<Integer> lst) {
+    private void inOrderAux(Node n, ArrayList<Integer> lst) {
         if (n == null) return;
-        in_order_aux(n.left, lst);
+        inOrderAux(n.left, lst);
         lst.add(n.element);
-        in_order_aux(n.right, lst);
+        inOrderAux(n.right, lst);
     }
 }

src/main/java/com/thealgorithms/datastructures/trees/GenericTree.java

@@ -25,10 +25,10 @@ public class GenericTree {
     private final Node root;
     public GenericTree() { // Constructor
         Scanner scn = new Scanner(System.in);
-        root = create_treeG(null, 0, scn);
+        root = createTreeG(null, 0, scn);
     }
 
-    private Node create_treeG(Node node, int childIndex, Scanner scanner) {
+    private Node createTreeG(Node node, int childIndex, Scanner scanner) {
         // display
         if (node == null) {
             System.out.println("Enter root's data");
@@ -41,7 +41,7 @@ public class GenericTree {
         System.out.println("number of children");
         int number = scanner.nextInt();
         for (int i = 0; i < number; i++) {
-            Node child = create_treeG(node, i, scanner);
+            Node child = createTreeG(node, i, scanner);
             node.child.add(child);
         }
         return node;
@@ -51,17 +51,17 @@ public class GenericTree {
      * Function to display the generic tree
      */
     public void display() { // Helper function
-        display_1(root);
+        display1(root);
     }
 
-    private void display_1(Node parent) {
+    private void display1(Node parent) {
         System.out.print(parent.data + "=>");
         for (int i = 0; i < parent.child.size(); i++) {
             System.out.print(parent.child.get(i).data + " ");
         }
         System.out.println(".");
         for (int i = 0; i < parent.child.size(); i++) {
-            display_1(parent.child.get(i));
+            display1(parent.child.get(i));
         }
     }
 

src/main/java/com/thealgorithms/datastructures/trees/nearestRightKey.java

@@ -8,7 +8,7 @@ final class NearestRightKey {
     }
 
     public static void main(String[] args) {
-        NRKTree root = BuildTree();
+        NRKTree root = buildTree();
         Scanner sc = new Scanner(System.in);
         System.out.print("Enter first number: ");
         int inputX0 = sc.nextInt();
@@ -17,7 +17,7 @@ final class NearestRightKey {
         sc.close();
     }
 
-    public static NRKTree BuildTree() {
+    public static NRKTree buildTree() {
         int randomX = ThreadLocalRandom.current().nextInt(0, 100 + 1);
         NRKTree root = new NRKTree(null, null, randomX);