Java Program To Implement Binomial Tree

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import java.util.*;

class BinoNode {
	int data;
	int numNodes;
	BinoNode arr[];

	public BinoNode(int k) {
		data = -1;
		numNodes = k;
		arr = new BinoNode[numNodes];
	}
}

class BinomialTree {
	private BinoNode root;
	private int order, size;

	public BinomialTree(int k) {
		size = 0;
		order = k;
		root = new BinoNode(order);
		createTree(root);
	}

	private void createTree(BinoNode r) {
		int n = r.numNodes;
		if (n == 0)
			return;
		for (int i = 0; i < n; i++) {
			r.arr[i] = new BinoNode(i);
			createTree(r.arr[i]);
		}
	}

	public void clear() {
		size = 0;
		root = new BinoNode(order);
		createTree(root);
	}

	public boolean isEmpty() {
		return size == 0;
	}

	public int getSize() {
		return size;
	}

	public void insert(int val) {
		try {
			insert(root, val);
		} catch (Exception e) {
		}
	}

	private void insert(BinoNode r, int val) throws Exception {
		if (r.data == -1) {
			r.data = val;
			size++;
			throw new Exception("inserted !");
		}
		int n = r.numNodes;
		for (int i = 0; i < n; i++)
			insert(r.arr[i], val);
	}

	public void printTree() {
		System.out.print("\nBinomial Tree = ");
		printTree(root);
		System.out.println();
	}

	private void printTree(BinoNode r) {
		if (r.data != -1)
			System.out.print(r.data + " ");
		int n = r.numNodes;
		if (n == 0)
			return;
		for (int i = 0; i < n; i++)
			printTree(r.arr[i]);
	}
}

public class JavaBinomialTree {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		System.out.println("Binomial Tree Test\n");
		System.out.println("\nEnter order of binomial tree");
		/** Creating object of Binomial tree **/
		BinomialTree bt = new BinomialTree(scanner.nextInt());
		char ch;
		/** Perform tree operations **/
		do {
			System.out.println("\nBinomial Tree Operations\n");
			System.out.println("1. insert ");
			System.out.println("2. size");
			System.out.println("3. check empty");
			System.out.println("4. clear");

			int choice = scanner.nextInt();
			switch (choice) {
			case 1:
				System.out.println("Enter integer element to insert");
				bt.insert(scanner.nextInt());
				break;
			case 2:
				System.out.println("Nodes = " + bt.getSize());
				break;
			case 3:
				System.out.println("Empty status = " + bt.isEmpty());
				break;
			case 4:
				bt.clear();
				System.out.println("\nTree Cleared\n");
				break;
			default:
				System.out.println("Wrong Entry \n ");
				break;
			}
			/** Display tree **/
			bt.printTree();

			System.out.println("\nDo you want to continue (Type y or n) \n");
			ch = scanner.next().charAt(0);
		} while (ch == 'Y' || ch == 'y');
	}
}
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