def compute_exact_score(predictions, target_lists):
    """Computes the Exact score (accuracy) of the predictions.

    Exact score is defined as the percentage of predictions that match at least
    one of the targets.

    Args:
        predictions: List of predictions.
        target_lists: List of targets (1 or more per prediction).

    Returns:
        Exact score between [0, 1].
    """
    num_matches = sum(any(pred == target for target in targets) for pred, targets in zip(predictions, target_lists))
    return num_matches / max(len(predictions), 0.1)