Remove unnecessary code (#4141)

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

@@ -49,8 +49,7 @@ public class AVLSimple {
 
     private Node insert(Node node, int item) {
         if (node == null) {
-            Node add = new Node(item);
-            return add;
+            return new Node(item);
         }
         if (node.data > item) {
             node.left = insert(node.left, item);

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

@@ -62,21 +62,20 @@ public class AVLTree {
             }
             return;
         }
+        Node child;
         if (node.left != null) {
-            Node child = node.left;
+            child = node.left;
             while (child.right != null) {
                 child = child.right;
             }
-            node.key = child.key;
-            delete(child);
         } else {
-            Node child = node.right;
+            child = node.right;
             while (child.left != null) {
                 child = child.left;
             }
-            node.key = child.key;
-            delete(child);
         }
+        node.key = child.key;
+        delete(child);
     }
 
     public void delete(int delKey) {
@@ -216,11 +215,7 @@ public class AVLTree {
 
     public boolean search(int key) {
         Node result = searchHelper(this.root, key);
-        if (result != null) {
-            return true;
-        }
-
-        return false;
+        return result != null;
     }
 
     private Node searchHelper(Node root, int key) {

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

@@ -117,11 +117,9 @@ public class BinaryTree {
             if (value < parent.data) {
                 parent.left = newNode;
                 parent.left.parent = parent;
-                return;
             } else {
                 parent.right = newNode;
                 parent.right.parent = parent;
-                return;
             }
         }
     }
@@ -177,7 +175,6 @@ public class BinaryTree {
             if (temp == root) {
                 successor.parent = null;
                 root = successor;
-                return true;
             } // If you're not deleting the root
             else {
                 successor.parent = temp.parent;
@@ -188,8 +185,8 @@ public class BinaryTree {
                 } else {
                     temp.parent.left = successor;
                 }
-                return true;
             }
+            return true;
         } // One child
         else {
             // If it has a right child
@@ -207,7 +204,6 @@ public class BinaryTree {
                 } else {
                     temp.parent.right = temp.right;
                 }
-                return true;
             } // If it has a left child
             else {
                 if (temp == root) {
@@ -223,8 +219,8 @@ public class BinaryTree {
                 } else {
                     temp.parent.right = temp.left;
                 }
-                return true;
             }
+            return true;
         }
     }
 

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

@@ -168,7 +168,6 @@ public class GenericTree {
         for (int i = 0; i < node.child.size(); i++) {
             depth(node.child.get(i), dep - 1);
         }
-        return;
     }
 
     /**

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

@@ -309,23 +309,20 @@ public class RedBlackBST {
 
     public void insertDemo() {
         Scanner scan = new Scanner(System.in);
-        while (true) {
-            System.out.println("Add items");
+        System.out.println("Add items");
 
-            int item;
-            Node node;
+        int item;
+        Node node;
 
+        item = scan.nextInt();
+        while (item != -999) {
+            node = new Node(item);
+            insert(node);
             item = scan.nextInt();
-            while (item != -999) {
-                node = new Node(item);
-                insert(node);
-                item = scan.nextInt();
-            }
-            printTree(root);
-            System.out.println("Pre order");
-            printTreepre(root);
-            break;
         }
+        printTree(root);
+        System.out.println("Pre order");
+        printTreepre(root);
         scan.close();
     }
 

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

@@ -62,7 +62,7 @@ public class TrieImp {
             }
             currentNode = node;
         }
-        if (currentNode.end == true) {
+        if (currentNode.end) {
             currentNode.end = false;
             return true;
         }