Tree with variable amount of nodes

mn-tree.cpp

#include <iostream>
#include <queue>
#include <vector>
#include <memory>
#include <cstdarg>

using namespace std;

class Tree {
public:
	int value;
	vector<unique_ptr<Tree>> nextNodes;

	Tree(const int& nValue, int numNodes = 0, ...) : value(nValue) {
		va_list vl;
		va_start(vl, numNodes);
		for (int i = 0; i < numNodes; i++)
			nextNodes.push_back(unique_ptr<Tree>(va_arg(vl, Tree*)));
	}

	void depthFirst() const {
		cout << value << " ";
		for (auto &n : nextNodes)
			if (n)
				n->depthFirst();
	}

	void breadthFirst() const {
		queue<const Tree*> q;
		q.push(this);

		while(!q.empty()) {
			const Tree *n = q.front();
			q.pop();
			cout << n->value << " ";

			for (auto &node : n->nextNodes)
				if (node)
					q.push(node.get());
		}
	}

	void visualise() const {
		static int level = 0;
		for (int i = 0; i < level; i++)
			cout << "  ";

		cout << value << endl;
		for (auto &n : nextNodes) {
			if (n) {
				level++;
				n->visualise();
			}
			level--;
		}
	}
};

int main() {
	Tree root(1, 2,
			new Tree(2, 2,
				new Tree(4, 1,
					new Tree(7)),
				new Tree(5)),
			new Tree(3, 1,
				new Tree(6, 2,
					new Tree(8),
					new Tree(9))));

	cout << "depth-first:   ";
	root.depthFirst();
	cout << endl;

	cout << "breadth-first: ";
	root.breadthFirst();
	cout << endl;

	root.visualise();

	return 0;
}