import java.util.Iterator;
import java.util.List;
public class Vector2D implements Iterator {
private Iterator> mIterator;
private Iterator mSubIterator;
public Vector2D(List> vec2d) {
mIterator = vec2d.iterator();
}
@Override
public Integer next() {
if (hasNext()) {
return mSubIterator.next();
}
return 0;
}
@Override
public boolean hasNext() {
while (mSubIterator == null || !mSubIterator.hasNext()) {
if (mIterator.hasNext()) {
mSubIterator = mIterator.next().iterator();
} else {
break;
}
}
return mSubIterator != null && mSubIterator.hasNext();
}
}