DrinksTreeDsa

import java.util.ArrayList;
import java.util.List;

class Drink {
    private String name;
    private List<Drink> children;

    public Drink(String name) {
        this.name = name;
        this.children = new ArrayList<>();
    }

    public void addChild(Drink drink) {
        children.add(drink);
    }

    public String getName() {
        return name;
    }

    public List<Drink> getChildren() {
        return children;
    }
}

public class DrinkHierarchy {
    public static void main(String[] args) {
        // Create the drink hierarchy
        Drink root = new Drink("Drinks");

        Drink hot = new Drink("Hot");
        Drink cold = new Drink("Cold");
        root.addChild(hot);
        root.addChild(cold);

        Drink tea = new Drink("Tea");
        Drink coffee = new Drink("Coffee");
        hot.addChild(tea);
        hot.addChild(coffee);

        Drink greenTea = new Drink("Green Tea");
        Drink blackTea = new Drink("Black Tea");
        tea.addChild(greenTea);
        tea.addChild(blackTea);

        Drink americano = new Drink("Americano");
        Drink latte = new Drink("Latte");
        Drink cappuccino = new Drink("Cappuccino");
        coffee.addChild(americano);
        coffee.addChild(latte);
        coffee.addChild(cappuccino);

        Drink nonAlcoholic = new Drink("Non-Alcoholic");
        Drink alcoholic = new Drink("Alcoholic");
        cold.addChild(nonAlcoholic);
        cold.addChild(alcoholic);

        Drink cola = new Drink("Cola");
        Drink fanta = new Drink("Fanta");
        Drink soda = new Drink("Soda");
        nonAlcoholic.addChild(cola);
        nonAlcoholic.addChild(fanta);
        nonAlcoholic.addChild(soda);

        Drink wine = new Drink("Wine");
        Drink beer = new Drink("Beer");
        Drink whisky = new Drink("Whisky");
        alcoholic.addChild(wine);
        alcoholic.addChild(beer);
        alcoholic.addChild(whisky);

        // Print the drink hierarchy using pre-order traversal
        printDrinkHierarchy(root, 0);
    }

    public static void printDrinkHierarchy(Drink drink, int level) {
        StringBuilder indent = new StringBuilder();
        for (int i = 0; i < level; i++) {
            indent.append("  ");
        }

        System.out.println(indent + drink.getName());

        for (Drink child : drink.getChildren()) {
            printDrinkHierarchy(child, level + 1);
        }
    }
}