算法：号码转换问题

package practice;

import java.io.BufferedInputStream;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;

/**
 * @author caiyu
 * @date 2014-11-2
 */
public class MemorableTelNumber {
    public static void main(String[] args) {
        Scanner cin = new Scanner(new BufferedInputStream(System.in));
        int l = cin.nextInt();
        String num;
        Map<String, Integer> m = new TreeMap<String, Integer>();
        StringBuffer c;
        int tmp;
        String s;
        for (int i = 0; i < l; i++) {
            num = cin.next().trim();
            c = new StringBuffer();
            for (int j = 0, len = num.length(); j < len; j++) {
                tmp = handle(num.charAt(j));
                if (0 <= tmp && tmp <= 9)
                    c.append(tmp);
            }

            if (c.length() == 7) {
                c.insert(3, "-");
                s = c.toString();
                if (m.containsKey(s))
                    m.put(s, m.get(s) + 1);
                else
                    m.put(s, 1);
            }
        }

        for (String k : m.keySet()) {
            if (m.get(k) > 1)
                System.out.println(k + " " + m.get(k));
        }
    }

    private static int handle(char c) {
        if (c == 'A' || c == 'B' || c == 'C')
            return 2;
        if (c == 'D' || c == 'E' || c == 'F')
            return 3;
        if (c == 'G' || c == 'H' || c == 'I')
            return 4;
        if (c == 'J' || c == 'K' || c == 'L')
            return 5;
        if (c == 'M' || c == 'N' || c == 'O')
            return 6;
        if (c == 'P' || c == 'R' || c == 'S')
            return 7;
        if (c == 'T' || c == 'U' || c == 'V')
            return 8;
        if (c == 'W' || c == 'X' || c == 'Y')
            return 9;
        if (c == '-')
            return -1;
        return Integer.parseInt("" + c);
    }
}