input: Write a python function to perform linear regression using numpy.
  assert linear_reg([1, 2, 3, 4], [2, 3, 5, 7]) == (1.4, 0.1)
  assert linear_reg([1, 2, 3], [1, 2, 3]) == (1.0, 0.0)
  assert linear_reg([0, 1, 2], [0, 2, 4]) == (2.0, 0.0)
output: import numpy as np
  
  def linear_reg(x, y):
      x = np.array(x)
      y = np.array(y)
      A = np.vstack([x, np.ones(len(x))]).T
      m, c = np.linalg.lstsq(A, y, rcond=None)[0]
      return (m, c)