code: def compute_rewards(self, 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)
docs: Compute the velocity of the best scores
  
          The velocities are the k distances between the k+1 best scores.