[Java][АПС] - Растојание во дрво

import java.util.*;
import java.io.*;


class BNode<E> {

    public E info;
    public BNode<E> left;
    public BNode<E> right;

    static int LEFT = 1;
    static int RIGHT = 2;

    public BNode(E info) {
        this.info = info;
        left = null;
        right = null;
    }

    public BNode() {
        this.info = null;
        left = null;
        right = null;
    }

    public BNode(E info, BNode<E> left, BNode<E> right) {
        this.info = info;
        this.left = left;
        this.right = right;
    }

}

class BTree<E> {

    public BNode<E> root;

    public BTree() {
        root = null;
    }

    public BTree(E info) {
        root = new BNode<E>(info);
    }

    public void makeRoot(E elem) {
        root = new BNode(elem);
    }

    public void makeRootNode(BNode<E> node) {
        root = node;
    }

    public BNode<E> addChild(BNode<E> node, int where, E elem) {

        BNode<E> tmp = new BNode<E>(elem);

        if (where == BNode.LEFT) {
            if (node.left != null)  // veke postoi element
                return null;
            node.left = tmp;
        } else {
            if (node.right != null) // veke postoi element
                return null;
            node.right = tmp;
        }

        return tmp;
    }

    public BNode<E> addChildNode(BNode<E> node, int where, BNode<E> tmp) {

        if (where == BNode.LEFT) {
            if (node.left != null)  // veke postoi element
                return null;
            node.left = tmp;
        } else {
            if (node.right != null) // veke postoi element
                return null;
            node.right = tmp;
        }

        return tmp;
    }
    public BNode<E> korenNaDvata(BNode<E> od, BNode<E> doo){
    	return korenNaDvata(root,od,doo);
    }
    public BNode<E> korenNaDvata(BNode<E> node, BNode<E> od, BNode<E> doo){
    	if(node==null)
    		return null;
    	if(node==od||node==doo)
    		return node;
    	BNode<E> left = korenNaDvata(node.left,od,doo);
    	BNode<E> right = korenNaDvata(node.right,od,doo);

    	if(left!=null&&right!=null)
    		return node;
    	if(left!=null)
    		return left;
    	return right;
    }

    public BNode<E> find(BNode<E> node,String najdi){
    	if(node==null)
    		return null;
    	if(node.info.equals(najdi))
    		return node;
    	else {
    		BNode<E> left = find(node.left,najdi);
    		BNode<E> right = find(node.right,najdi);
    		if(left!=null)
    			return left;
    		return right;
    	}

    }

    public int najkratkaPateka(BNode<String> koren2, BNode<String> node,int brojac) {
		if(koren2 ==null)
			return 999999;
		if(koren2==node)
			return 0;
		brojac+=Math.min(najkratkaPateka(koren2.left, node,brojac)+1,najkratkaPateka(koren2.right,node,brojac)+1);
		return brojac;
	}
}

public class NodeDistance {

	public static void main(String[] args) throws IOException, Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		StringTokenizer st;

		BNode<String> [] nodes = new BNode[n];
		BTree<String> tree = new BTree<String>();
		for(int i=0;i<n;i++)
			nodes[i] = new BNode<String>();

		for(int i=0;i<n;i++) {
			String line = br.readLine();
			st = new StringTokenizer(line);
			int index = Integer.parseInt(st.nextToken());
			nodes[index].info = st.nextToken();
			String action = st.nextToken();
			if(action.equals("RIGHT")) {
				tree.addChildNode(nodes[Integer.parseInt(st.nextToken())], BNode.RIGHT, nodes[index]);
			}
			else if(action.equals("LEFT")) {
				tree.addChildNode(nodes[Integer.parseInt(st.nextToken())], BNode.LEFT, nodes[index]);
			}
			else {
				tree.makeRootNode(nodes[index]);
			}
		}
		int kolku = Integer.parseInt(br.readLine());
		for(int i=0;i<kolku;i++) {
			String [] dva = br.readLine().split(" ");
			String od = dva[0];
			String doo = dva[1];

			BNode<String> getfirst = tree.find(tree.root, od);
			BNode<String> getsecond = tree.find(tree.root,doo);
			if(getfirst==null||getsecond==null)
			{
				System.out.println("ERROR");
				continue;

			}


			BNode<String> koren2 = tree.korenNaDvata(getfirst, getsecond);

			int prv = (tree.najkratkaPateka(koren2,getfirst,0));
			int vtor = (tree.najkratkaPateka(koren2,getsecond,0));
			System.out.println((prv+vtor)*2);
		}


	}

}