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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def compute_rewards(self, scores):
 """Compute the velocity of the best scores The velocities are the k distances between the k+1 best scores. """

        k = self.k
        m = max(len(scores) - k, 0)
        best_scores = sorted(scores)[-k - 1:]
        velocities = np.diff(best_scores)
        nans = np.full(m, np.nan)
        return list(velocities) + list(nans)