(UVA) 487-3279 - Solution

Link to the problem: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=696

While reading the telephone numbers, they are all mapped to the common notation. Then, we only need to group the telephone numbers that are exactly the same in a structure that keeps not only the number, but also how many repetitions were found.


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

class Main {
    public static HashMap<Character, Integer> map;
   
    public static void initMap() {
        map.put('A', 2);
        map.put('B', 2);
        map.put('C', 2);
        map.put('D', 3);
        map.put('E', 3);
        map.put('F', 3);
        map.put('G', 4);
        map.put('H', 4);
        map.put('I', 4);
        map.put('J', 5);
        map.put('K', 5);
        map.put('L', 5);
        map.put('M', 6);
        map.put('N', 6);
        map.put('O', 6);
        map.put('P', 7);
        map.put('R', 7);
        map.put('S', 7);
        map.put('T', 8);
        map.put('U', 8);
        map.put('V', 8);
        map.put('W', 9);
        map.put('X', 9);
        map.put('Y', 9);
        map.put('1', 1);
        map.put('2', 2);
        map.put('3', 3);
        map.put('4', 4);
        map.put('5', 5);
        map.put('6', 6);
        map.put('7', 7);
        map.put('8', 8);
        map.put('9', 9);
        map.put('0', 0);
    }
   
    public static void process() throws NumberFormatException, IOException {
        Scanner sc = new Scanner(System.in);
   
        map = new HashMap<>();
        initMap();
              
        int numTests = sc.nextInt();
        for (int i = 0; i < numTests; i++) {
            if (i > 0) {
                System.out.println(); // blank space between output
            }
            TreeMap<String, Integer> phoneMap = new TreeMap<>();
            int numPhones = sc.nextInt();
            for (int j = 0; j < numPhones; j++) {
                String phone = sc.next();
                StringBuilder sb = new StringBuilder();
                for (int k = 0; k < phone.length(); k++) {
                    if (phone.charAt(k) == '-') {
                        continue;
                    }
                    if (sb.length() == 3) {
                        sb.append("-");
                    }
                    sb.append(map.get(phone.charAt(k)));
                }
                phone = sb.toString();
                if (!phoneMap.containsKey(phone)) {
                    phoneMap.put(phone, 0);
                }
                phoneMap.put(phone, phoneMap.get(phone)+1);
            }
           
            int count = 0;
            for (String s : phoneMap.keySet()) {
                if (phoneMap.get(s) > 1) {
                    System.out.println(s + " " + phoneMap.get(s));
                    count++;                   
                }
            }
            if (count == 0) {
                System.out.println("No duplicates.");
            }
        }
       
        return;
    }
   
    public static void main(String[] args) throws NumberFormatException, IOException {
        Main m = new Main();
        m.process();
       
        System.exit(0);
    }
}