import java.util.concurrent.ThreadLocalRandom;
import static java.lang.System.out;
final class Main {
public static void main(String[] args) {
var root = new Node(10);
for (int i = 0; i < 10; i++) {
root.add(new Node(ThreadLocalRandom.current().nextInt(20)));
}
out.println(new BinaryTree(root).size());
}
}
import static java.util.Objects.requireNonNull;
final class Node {
private Node left;
private Node right;
private final int value;
public Node(int value) {
this.value = value;
}
public int value() {
return value;
}
public Node left() {
return left;
}
public Node right() {
return right;
}
public Node add(Node node) {
requireNonNull(node);
if (node.value < value) {
if (left == null) {
left = node;
} else {
left.add(node);
}
} else {
if (right == null) {
right = node;
} else {
right.add(node);
}
}
return this;
}
@Override
public String toString() {
return String.format("[%s, %s, %s]", left == null ? null : left.value, value, right == null ? null : right.value);
}
}
final class BinaryTree {
private final Node root;
public BinaryTree(Node root) {
this.root = root;
}
public BinaryTree() {
this(null);
}
public int size() {
return calculateSize(root);
}
private int calculateSize(Node root) {
return root == null ? 0 : 1 + calculateSize(root.left()) + calculateSize(root.right());
}
@Override
public String toString() {
return String.format("[%s]", toString(root));
}
private String toString(Node root) {
StringBuilder stringBuilder = new StringBuilder();
if (root == null) {
return "null";
}
stringBuilder.append(root.value());
stringBuilder.append("\nleft:\t");
stringBuilder.append(toString(root.left()));
stringBuilder.append("\nright:\t");
stringBuilder.append(toString(root.right()));
return stringBuilder.toString();
}
}
