I didn't want to recalculate the squares. :)

class Solution:
  def makeSquares(self, arr):
    n = len(arr)
    squares = [0] * n
    left, right, i = 0, n - 1, n - 1
    sq_left = arr[left]**2
    sq_right = arr[right]**2
    while i >= 0:
      if sq_left > sq_right:
        squares[i] = sq_left
        left += 1
        sq_left = arr[left]**2
      else:
        squares[i] = sq_right
        right -= 1
        sq_right = arr[right]**2
      i -= 1

    return squares