fix: check perfect squares with math.isqrt instead of floats

math.sqrt(num) * math.sqrt(num) == num rounds: it holds for 11, 14, 17 and about half of all other non-squares below 200000, and fails for large squares such as (2**53 + 1) ** 2. math.isqrt is exact, and the result now agrees with perfect_square_binary_search() for every n below 300000.

Author: L4XB

maths/perfect_square.py

@@ -17,8 +17,12 @@ def perfect_square(num: int) -> bool:
     True
     >>> perfect_square(10)
     False
+    >>> perfect_square(11)
+    False
+    >>> perfect_square((2**53 + 1) ** 2)
+    True
     """
-    return math.sqrt(num) * math.sqrt(num) == num
+    return math.isqrt(num) ** 2 == num
 
 
 def perfect_square_binary_search(n: int) -> bool: