btree

#include <iostream>
#include <vector>

// Macro to reduce code
#define add(n) children.push_back(n)

using namespace std;

class Node
{
	public:
		Node(string pName) : name(pName) {}
		~Node() { for(int i = 0; i < this->children.size();) delete this->children.at(i++); }
		string name;
		vector<Node *> children;

};

Node * tree;
// Tree:
//                A   		-> root
//             B  |  C |  D	-> first level
//        E   F   | G  |	-> second level 
//     H I J | K|			-> third level
void buildTree()
{
	// Root of the tree
	tree = new Node("a");
	Node * a = tree;

	// Nodes to build tree
	Node * b, * c, * d, * e, * f, * g, * h, * i, * j, * k;
	b = new Node("b"), c = new Node("c"), d = new Node("d"), 
	e = new Node("e"), f = new Node("f"), g = new Node("g"), 
	h = new Node("h"), i = new Node("i"), j = new Node("j"), 
	k = new Node("k");

	// Children of A
	a->add(b), a->add(c), a->add(d);

	// Children of B
	b->add(e), b->add(f);

	// Children of C
	c->add(g);

	// Children of E
	e->add(h), e->add(i), e->add(j);

	// Children of F
	f->add(k); 
}

// Print node, go left and then right, recursively
void VLR(Node * node, string prefix)
{
	prefix += node->name;
	cout << prefix << ":";

	// Visit following nodes
	for(int i = 0; i < node->children.size();)
		VLR(node->children.at(i++), prefix);
}

// go left, print node and then right, recursively
void LVR(Node * node, string prefix)
{
	prefix += node->name;

	// Visit following nodes
	for(int i = 0; i < node->children.size();)
		LVR(node->children.at(i++), prefix);

	cout << prefix << ":";
}

int main()
{
	buildTree();
	VLR(tree, ""), cout << endl;
	LVR(tree, ""), cout << endl;
	return 0;
}