CppPatterns/Composite/main.cpp

#include <iostream>
#include <string>
#include <vector>

class Node {
public:
  virtual ~Node() = default;
  virtual void print() const = 0;
};

class InnerNode : public Node {
private:
  std::string name_;
  std::vector<Node *> children_;

public:
  InnerNode(std::string_view name) : name_(name) {}

  void addNode(Node *node) { children_.push_back(node); }

  void print() const override {
    std::cout << name_ << " (inner)" << std::endl;

    for (auto child : children_) {
      child->print();
    }
  }
};

class Leaf : public Node {
private:
  std::string name_;

public:
  Leaf(std::string_view name) : name_(name) {}

  void print() const override { std::cout << name_ << " (leaf)" << std::endl; }
};

int main(int argc, char *argv[]) {

  std::cout << "Composite" << std::endl;

  InnerNode tree("root");
  InnerNode left("left"), right("right");
  Leaf leaf1("leaf 1"), leaf2("leaf 2"), leaf3("leaf 3"), leaf4("leaf 4");

  tree.addNode(&left);
  tree.addNode(&right);

  left.addNode(&leaf1);
  left.addNode(&leaf2);

  right.addNode(&leaf3);
  right.addNode(&leaf4);

  tree.print();

  return EXIT_SUCCESS;
}