def deduplicate_tracks(tracks):
    seen = set()
    unique = []

    for t in tracks:
        if t["id"] not in seen:
            seen.add(t["id"])
            unique.append(t)

    return unique

def diversify_tracks(tracks):
    result = []
    artist_count = {}

    for t in tracks:
        artist = t["artists"][0]["name"]
        count = artist_count.get(artist, 0)

        if count < 2:
            result.append(t)
            artist_count[artist] = count + 1

    return result