import numpy as np
import typing


class MinMaxScaler:
    def __init__(self):
        self.min_vals = None
        self.max_vals = None

    def fit(self, data: np.ndarray) -> None:
        self.min_vals = np.min(data, axis=0)
        self.max_vals = np.max(data, axis=0)

        return

    def transform(self, data: np.ndarray) -> np.ndarray:
        return (data - self.min_vals) / (self.max_vals - self.min_vals)


class StandardScaler:
    def __init__(self):
        self.mean_vals = None
        self.std_vals = None

    def fit(self, data: np.ndarray) -> None:
        self.mean_vals = np.mean(data, axis=0)
        self.std_vals = np.std(data, axis=0)

        return

    def transform(self, data: np.ndarray) -> np.ndarray:
        return (data - self.mean_vals) / self.std_vals