docs: def _populate_blotto_payoff_arrays(payoff_arrays, actions, values):
      """
      Populate the ndarrays in `payoff_arrays` with the payoff values of
      the Blotto game with h hills and t troops.
  
      Parameters
      ----------
      payoff_arrays : tuple(ndarray(float, ndim=2))
          Tuple of 2 ndarrays of shape (n, n), where n = (t+h-1)!/
          (t!*(h-1)!). Modified in place.
      actions : ndarray(int, ndim=2)
          ndarray of shape (n, h) containing all possible actions, i.e.,
          h-part compositions of t.
      values : ndarray(float, ndim=2)
          ndarray of shape (h, 2), where `values[k, :]` contains the
          players' values of hill `k`.
  
      """
      n, h = actions.shape
      payoffs = np.empty(2)
      for i in range(n):
          for j in range(n):
              payoffs[:] = 0
              for k in range(h):
                  if actions[i, k] == actions[j, k]:
                      for p in range(2):
                          payoffs[p] += values[k, p] / 2
                  else:
                      winner = np.int(actions[i, k] < actions[j, k])
                      payoffs[winner] += values[k, winner]
              payoff_arrays[0][i, j], payoff_arrays[1][j, i] = payoffs