import java.util.ArrayList;

public class TreeNode<T> {
    private T element;
    private TreeNode<T> parent;
    private ArrayList<TreeNode<T>> children;

    public TreeNode(T element) {
        this.element = element;
    }

    public int size() {
        return children.size();
    }

    public T getElement() {
        return element;
    }

    public void setElement(T element) {
        this.element = element;
    }

    public boolean isRoot() {
        if(parent == null) {
            return true;
        }
        return false;
    }

    public boolean isExternal() {
        if(children == null)
            return true;
        return false;
    }

    public boolean isInternal() {
        if(children != null)
            return true;
        return false;
    }

    public TreeNode<T> getParent() {
        return parent;
    }

    public ArrayList<TreeNode<T>> getChildren(){
        return children;
    }
}