Find the longest common starting substring in a set of strings [closed]

Answer 1

My solution in Java:

public static String compute(Collection strings) {
    if(strings.isEmpty()) return "";
    Set v = new HashSet();
    int i = 0;
    try {
        while(true) {
            for(String s : strings) v.add(s.charAt(i));
            if(v.size() > 1) break;
            v.clear();
            i++;
        }
    } catch(StringIndexOutOfBoundsException ex) {}
    return strings.iterator().next().substring(0, i);
}