题解 | 多项式特征的Phi变换

import numpy as np
def phi_transform(data: list[float], degree: int) -> list[list[float]]:
	"""
	Perform a Phi Transformation to map input features into a higher-dimensional space by generating polynomial features.

	Args:
		data (list[float]): A list of numerical values to transform.
		degree (int): The degree of the polynomial expansion.

	Returns:
		list[list[float]]: A nested list where each inner list represents the transformed features of a data point.
	"""
	if degree<0 or len(data)==0:
		return []
	data_arr=np.array(data,dtype=np.float64)
	degrees=np.arange(degree+1)
	res=data_arr.reshape(-1,1)**degrees
	return res.tolist()
if __name__ == "__main__":
    data = eval(input())
    degree = int(input())
    print(phi_transform(data, degree))