abstract class Component {
    protected parent: Component | null = null;
    public setParent(parent: Component | null) {
        this.parent = parent;
    }
    public getParent(): Component | null {
        return this.parent;
    }
    public add(component: Component): void { }
    public remove(component: Component): void { }
    public isComposite(): boolean {
        return false;
    }
    public abstract operation(): string;
}

class Leaf extends Component {
    public operation(): string {
        return 'Лист';
    }
}

class Composite extends Component {
    protected children: Component[] = [];

    public add(component: Component): void {
        this.children.push(component);
        component.setParent(this);
    }

    public remove(component: Component): void {
        const componentIndex = this.children.indexOf(component);
        this.children.splice(componentIndex, 1);

        component.setParent(null);
    }

    public isComposite(): boolean {
        return true;
    }

    public operation(): string {
        const results = [];
        for (const child of this.children) {
            results.push(child.operation());
        }

        return `Ветка(${results.join('+')})`;
    }
}

const tree = new Composite();
const branch1 = new Composite();
branch1.add(new Leaf());
branch1.add(new Leaf());
const branch2 = new Composite();
branch2.add(new Leaf());
tree.add(branch1);
tree.add(branch2);

console.log(tree.operation());