Parsing a parenthetic representation of a string to tree

Question

I have a little assignment and I have no thoughts at all anymore. I must convert a string ( like A(B,C) or A(B(C,D), E(F)) ) that represents a left-representation of binary tree. I must convert into a object and after that turn it around - I must make a right-representation of a string from object.
I made a class below:
import java.util.*;
public class kodutoo_5 implements Enumeration<kodutoo_5> {
     private String name;
     private kodutoo_5 firstChild;
     private kodutoo_5 nextSibling;
     kodutoo_5(String n, kodutoo_5 d, kodutoo_5 r) {
          setName(n);
          setNextSibling(d);
          setFirstChild(r);
     kodutoo_5() {
          this("", null, null);
     kodutoo_5(String n) {
          this(n, null, null);
     public String getName() {
          return name;
     public void setName(String name) {
          this.name = name;
     public kodutoo_5 getFirstChild() {
          return firstChild;
     public void setFirstChild(kodutoo_5 firstChild) {
          this.firstChild = firstChild;
     public kodutoo_5 getNextSibling() {
          return nextSibling;
     public void setNextSibling(kodutoo_5 nextSibling) {
          this.nextSibling = nextSibling;
     public String toString() {
          return getName();
     public boolean hasMoreElements() {
          return (getNextSibling() != null);
     public kodutoo_5 nextElement() {
          return getNextSibling();
     public Enumeration<kodutoo_5> child() {
          return getFirstChild();
     private static kodutoo_5 addChild(kodutoo_5 parent, kodutoo_5 current, String nodeString) {
          kodutoo_5 result = current;
          //kui alluvaid ei ole, siis jarelikult juurtipp
          if(parent.getFirstChild() == null) {
               //lisame alluva
               parent.setFirstChild(new kodutoo_5(nodeString));
               result = parent.getFirstChild();
          //alluvaid on
          } else {
               result.setNextSibling(new kodutoo_5(nodeString));
               result = result.getNextSibling();
          return result;
     public static kodutoo_5 parseTree(String s) {
          kodutoo_5 emptyRoot = new kodutoo_5();
          parseTree(emptyRoot, s);
          return emptyRoot.getFirstChild();
     private static void parseTree(kodutoo_5 parent, String s) {
          kodutoo_5 current = null;
          StringTokenizer st = new StringTokenizer(s, "(),", true);
          StringBuilder sb = new StringBuilder();
          while(st.hasMoreTokens()) {
               String element = st.nextToken();
               if(element.compareTo("(") == 0) {
                    if(sb.length() > 0) {
                         current = addChild(parent, current, sb.toString());
                         sb = new StringBuilder();
               } else if(element.compareTo(")") == 0) {
                    if(sb.length() > 0) {
                         current = addChild(parent, current, sb.toString());
                         sb = new StringBuilder();
               } else if(element.compareTo(",") == 0) {
                    if(sb.length() > 0) {
                         current = addChild(parent, current, sb.toString());
                         sb = new StringBuilder();
               } else {
                    sb.append(element);
          if(sb.length() > 0) {
               current = addChild(parent, current, sb.toString());
     public String rightParentheticRepresentation() {
          StringBuilder sb = new StringBuilder();
          //kontrollime kas juurtipp eksisteerib
          if (getName() == null) {
               throw new NullPointerException("Puud ei eksisteeri!");
          //kontrollime ega juurtipp tuhi ei ole
          if (getName() == "") {
               throw new RuntimeException("Puud ei eksisteeri!");
          //juurtipp eksisteerib, jarelikult ka puu
          if (getFirstChild() != null) {
               sb.append("(");
               sb.append(getFirstChild().rightParentheticRepresentation());
               Enumeration<kodutoo_5> child = child();
               while (child.hasMoreElements()) {
                    sb.append(",");
                    child = child.nextElement();
                    sb.append(((kodutoo_5) child).rightParentheticRepresentation());
               sb.append(")");
          sb.append(getName());
          return sb.toString();
     public static void main(String[] args) {
          String s1 = "A(B,C)";
          //String s2 = "A(B(C,D),E(F))";
          kodutoo_5 t1 = kodutoo_5.parseTree(s1);
          //kodutoo_5 t2 = kodutoo_5.parseTree(s2);
          String v1 = t1.rightParentheticRepresentation();
          //String v2 = t2.rightParentheticRepresentation();
          System.out.println(s1 + " ==> " + v1);
          //System.out.println(s2 + " ==> " + v2);
}But I can't make it right. Can anybody help me out to make this code work, please? Or point me what I'm doing wrong here?

Answer 1

Add debugging statements to your code to see what it's doing and where it's going wrong.