(SPOJ) 1334 - Calculando - Solução

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

class Main {
    public static void main(String[] args) throws NumberFormatException, IOException {
        Main processando = new Main();
        processando.processa();
       
        System.exit(0);
    }
   
    void processa() throws NumberFormatException, IOException {
        String line = "";
       
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        int contador = 0;
        while ((line = br.readLine()) != null) {
            StringTokenizer tokenizer = new StringTokenizer(line);
            int numOperandos = Integer.valueOf(tokenizer.nextToken());

            if (numOperandos == 0) {
                return;
            }
           
            contador++;
            System.out.println("Teste " + contador);
           
            line = br.readLine();
            line = "+" + line;

            String num = "";

            int resultado = 0;
            boolean entrouWhile = false;
           
            for (int i = 0; i < line.length(); i++) {
                if (line.charAt(i) == '+') {
                    int j = i+1;
                    while (j < line.length() && line.charAt(j) != '+' && line.charAt(j) != '-') {
                        num += line.charAt(j);
                        j++;
                        entrouWhile = true;
                    }
                    if (entrouWhile) {
                        i = j-1;
                        entrouWhile = false;
                    }
                    resultado += Integer.valueOf(num);
                    num = "";
                }
                else if (line.charAt(i) == '-') {
                    int j = i+1;
                    while (j < line.length() && line.charAt(j) != '+' && line.charAt(j) != '-') {
                        num += line.charAt(j);
                        j++;
                        entrouWhile = true;
                    }
                    if (entrouWhile) {
                        i = j-1;
                        entrouWhile = false;
                    }   
                    resultado -= Integer.valueOf(num);
                    num = "";
                }
               
            }           
           
           
            System.out.println(resultado);
           
            System.out.println();
           
           
        }                            
                
        return;
    }
}