为什么有时候AC有时候RTE？？
这是咋回事？
import java.util.*;

public class Main {

	/**
	 * @param args
	 */
	public static String convert(String s)
	{
		String out = "";
		char bit;
		for(int i = 0; i < s.length(); i++)
		{
			bit = s.charAt(i);
			if(bit >= '0' && bit <= '9')
				out += bit;
			else if(bit == 'A' || bit == 'B' || bit == 'C')
				out += '2';
			else if(bit == 'D' || bit == 'E' || bit == 'F')
				out += '3';
			else if ( bit == 'G' || bit == 'H' || bit == 'I')
                out += "4";
            else if (bit == 'J' || bit == 'K' || bit == 'L')
                 out += "5";
             else if (bit == 'M' || bit == 'N' || bit == 'O')
            	 out += "6";
             else if (bit == 'P' || bit == 'R' || bit == 'S')
            	 out += "7";
             else if (bit == 'T' || bit == 'U' || bit == 'V')
            	 out += "8";
             else if (bit == 'W' || bit == 'Y' || bit == 'X')
            	 out += "9";
		}
		return out.substring(0, 3) + "-" + out.substring(3);
	}
	
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int n;
		String inString;
		
		Scanner input = new Scanner(System.in);
		n = input.nextInt();
		HashMap<String, Integer> hashTable = new HashMap<String, Integer>();
		for(int i = 0; i < n; i++)
		{
			inString = input.next();
			inString = convert(inString);
			if(hashTable.get(inString) == null)
				hashTable.put(inString, 1);
			else
			{
				int newVal = hashTable.get(inString) + 1;
				hashTable.put(inString, newVal);
			}
				
		}
		if(hashTable.keySet().size() == n)
			System.out.println("No duplicates.");
		else
		{
			ArrayList<num> list = new ArrayList<num>();
			for(Map.Entry<String, Integer> entry : hashTable.entrySet())
			{
				if(entry.getValue() > 1)
					list.add(new num(entry.getKey(), entry.getValue()));
			}
			
			Collections.sort(list, new Comparator()
			{
				public int compare(Object arg0, Object arg1)
				{
                    num c1 = (num) arg0;
                    num c2 = (num) arg1;
                    
                    return c1.phoneNum.compareTo(c2.phoneNum);
				}
			});
			for(num a : list)
			{
				System.out.println(a.phoneNum + " " + a.appTimes);
			}
		}
	}
	
}

class num
{
	String phoneNum;
	int appTimes;
	public num(String aNum, int aTimes)
	{
		phoneNum = aNum;
		appTimes = aTimes;
	}
}