public int addLeaf(Node root, Node leaf) {
		Node node = this.leafs.get(leaf.getInfo());
		
		if (node!=null) {
			return -1;
		}
		
		if (root==null && this.head==null) {	// no se el padre y no hay head -> head = leaf
			this.head = leaf;
			this.leafs.put(leaf.getInfo(), leaf);
			
		} else if (root==null && this.head != null) {	// si no se el padre y hay head -> root = head
			leaf.setPadre(this.head);
			this.head.addHijo(leaf);
			this.leafs.put(leaf.getInfo(), leaf);
			
		} else if (root!=null && this.head==null) {		// se el padre y no hay head -> head = root / root.addhijo(leaf)
			this.head = root;
			this.leafs.put(root.getInfo(), root);
			
			leaf.setPadre(root);
			this.head.addHijo(leaf);
			this.leafs.put(leaf.getInfo(), leaf);
			
		} else { // (root!=null && this.head!=null) 	hay padre y hay hijo root.addhijo(leaf)
			
			leaf.setPadre(root);
			this.leafs.get(root.getInfo()).addHijo(leaf);
			this.leafs.put(leaf.getInfo(), leaf);
		}
		
		return 0;
	}