private void traverse(Node<T, V> subTree) {
if (subTree == null) {
return;
} else {
System.out.print(subTree.t + " ");
traverse(subTree.leftChild);
traverse(subTree.rightChild);
}
}
@Override
public String toString() {
// TODO Auto-generated method stub
// preroot to show the structure of this tree
traverse(tree);
return "-- Pre-root traverse of the current tree.";
}