UVa 00187 - Transaction Processing (an accounting problem )

Link: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=3&page=show_problem&problem=123
Sol:

package uva;
	import java.io.*;
	import java.util.*;
	public class UVa00187_TransactionProcessing {
	static class TransactionLine {
	String seq;
	String acc;
	double val;
	public TransactionLine(String seq, String acc, double val) {
	this.seq = seq;
	this.acc = acc;
	this.val = val;
	}
	}
	public static void main(String[] args) {
	InputReader in = new InputReader(System.in);
	HashMap<String, String> accounts = new HashMap<String, String>();
	while (true) {
	String acc = in.nextLine();
	if (acc.startsWith("000"))
	break;
	String number = acc.substring(0, 3);
	String name = acc.substring(3);
	accounts.put(number, name);
	}
	ArrayList<TransactionLine> lines = new ArrayList<TransactionLine>();
	String prev = "";
	while (true) {
	String line = in.nextLine();
	if (line.startsWith("000"))
	break;
	String seq = line.substring(0, 3);
	String acc = line.substring(3, 6);
	double val = Double.parseDouble(line.substring(6).trim()) / 100.0;
	if (!seq.equals(prev)) {
	double sum = 0.0;
	for (TransactionLine l : lines) {
	sum += l.val;
	}
	if (sum != 0.0) {
	System.out.println("*** Transaction " + lines.get(0).seq + " is out of balance ***");
	for (TransactionLine l : lines) {
	StringBuilder sb = new StringBuilder();
	sb.append(l.acc + " ");
	sb.append(accounts.get(l.acc));
	for (int i = 0; i < 30 - accounts.get(l.acc).length(); ++i)
	sb.append(" ");
	sb.append(" ");
	sb.append(String.format(Locale.ENGLISH, "%10.2f", l.val));
	System.out.println(sb);
	}
	System.out.println("999 Out of Balance " + String.format(Locale.ENGLISH, "%10.2f", Math.abs(sum)));
	System.out.println();
	}
	lines.clear();
	prev = seq;
	}
	lines.add(new TransactionLine(seq, acc, val));
	}
	}
	static class InputReader {
	public BufferedReader reader;
	public StringTokenizer tokenizer;
	public InputReader(InputStream stream) {
	reader = new BufferedReader(new InputStreamReader(stream));
	tokenizer = null;
	}
	public String next() {
	try {
	while (tokenizer == null || !tokenizer.hasMoreTokens())
	tokenizer = new StringTokenizer(reader.readLine());
	} catch (IOException e) {
	throw new RuntimeException(e);
	}
	return tokenizer.nextToken();
	}
	public String nextLine() {
	String line = null;
	try {
	tokenizer = null;
	line = reader.readLine();
	} catch (IOException e) {
	throw new RuntimeException(e);
	}
	return line;
	}
	public int nextInt() {
	return Integer.parseInt(next());
	}
	public double nextDouble() {
	return Double.parseDouble(next());
	}
	public long nextLong() {
	return Long.parseLong(next());
	}
	}
	}