Валидатор принял такой вариант, но...
Process finished with exit code 0
public class Solution {
public static void main(String[] args) throws IOException {
List<String> list = new ArrayList<>(Arrays.asList(args).subList(1, args.length));
Collections.sort(list);
List<InputStream> list2 = new ArrayList<>();
for (String s : list) {
list2.add(new FileInputStream(s));
}
FileOutputStream fos = new FileOutputStream(args[0]);
try(ZipInputStream zis = new ZipInputStream(new SequenceInputStream(Collections.enumeration(list2)))) {
while(zis.getNextEntry()!=null) {
byte[] buffer = new byte[1024];
int countOfBytes;
while ((countOfBytes = zis.read(buffer)) > 0) {
fos.write(buffer, 0, countOfBytes);
fos.flush();
}
zis.closeEntry();
}
/*int b;
while (true){
b = zis.read();
if (b==-1)break;
fos.write(b);
}
fos.flush();*/
}
catch (Exception e){
e.printStackTrace();
}
fos.close();
}
}