هل يمكن شرح هذا الكود؟ و هل هناك طريقة أفضل لعمل BinarySearchTree؟

public class BinaryTree2 { class Node { int key; Node left, right; public Node(int item) { key = item; left = right = null; } } // Root of BST Node root; // Constructor BinaryTree2() { root = null; } void deleteKey(int key) { root = deleteRec(root, key); } Node deleteRec(Node root, int key) { /* Base Case: If the tree is empty */ if (root == null) return root; /* Otherwise, recur down the tree */ if (key < root.key) root.left = deleteRec(root.left, key); else if (key > root.key) root.right = deleteRec(root.right, key); // if key is same as root's // key, then This is the // node to be deleted else { // node with only one child or no child if (root.left == null) return root.right; else if (root.right == null) return root.left; // node with two children: Get the inorder // successor (smallest in the right subtree) root.key = minValue(root.right); // Delete the inorder successor root.right = deleteRec(root.right, root.key); } return root; } int minValue(Node root) { int minv = root.key; while (root.left != null) { minv = root.left.key; root = root.left; } return minv; } // This method mainly calls insertRec() void insert(int key) { root = insertRec(root, key); } /* A recursive function to insert a new key in BST */ Node insertRec(Node root, int key) { /* If the tree is empty, return a new node */ if (root == null) { root = new Node(key); return root; } /* Otherwise, recur down the tree */ if (key < root.key) root.left = insertRec(root.left, key); else if (key > root.key) root.right = insertRec(root.right, key); /* return the (unchanged) node pointer */ return root; } // This method mainly calls InorderRec() void inorder() { inorderRec(root); } // A utility function to // do inorder traversal of BST void inorderRec(Node root) { if (root != null) { inorderRec(root.left); System.out.println(root.key); inorderRec(root.right); } } }