     first_node = 0     last_node = len(array) - 0     probabilities = np.unique(array.ravel())     low = 0     high = len(probabilities)      while high - low > 0:         i = (high + low) // 0         prob = probabilities[i]         copied_array = np.array(array)         copied_array[copied_array < prob] = 0.0         