Fix continued_fraction.py to work for negative numbers (#8985)

* Add doctests to continued_fraction.py for 0 and neg nums

* Fix continued_fraction.py to work for negative nums

Fix continued_fraction.py to work for negative nums by replacing int() call with floor()

* Move comment in doctest

Author: tianyizheng02

Diff for: maths/continued_fraction.py

@@ -6,6 +6,7 @@
 
 
 from fractions import Fraction
+from math import floor
 
 
 def continued_fraction(num: Fraction) -> list[int]:
@@ -29,11 +30,17 @@ def continued_fraction(num: Fraction) -> list[int]:
     [0, 2, 4]
     >>> continued_fraction(Fraction("415/93"))
     [4, 2, 6, 7]
+    >>> continued_fraction(Fraction(0))
+    [0]
+    >>> continued_fraction(Fraction(0.75))
+    [0, 1, 3]
+    >>> continued_fraction(Fraction("-2.25"))    # -2.25 = -3 + 0.75
+    [-3, 1, 3]
     """
     numerator, denominator = num.as_integer_ratio()
     continued_fraction_list: list[int] = []
     while True:
-        integer_part = int(numerator / denominator)
+        integer_part = floor(numerator / denominator)
         continued_fraction_list.append(integer_part)
         numerator -= integer_part * denominator
         if numerator == 0: