@@ -0,0 +1,564 @@
+public class Explorer%0A%7B%0A    public static final int MAXIMUM_KEYS = 26;%0A%0A    public Explorer ()%0A    %7B%0A        _keys = new char%5BMAXIMUM_KEYS%5D;%0A        _keysFound = 0;%0A    %7D%0A%0A    @Override%0A    public String toString ()%0A    %7B%0A        if (_keysFound %3E 0)%0A        %7B%0A            String str = %22Keys found: %22;%0A%0A            for (int i = 0; i %3C _keysFound; i++)%0A            %7B%0A                str += %22, %22+_keys%5Bi%5D;%0A            %7D%0A%0A            return str;%0A        %7D%0A        else%0A            return %22No keys found.%22;%0A    %7D%0A%0A    private char%5B%5D _keys;%0A    private int _keysFound;%0A%7D

Update Explorer.java