Make extreme-variance more strict, add hints. Fixed laike9m#89

Author: laike9m

challenges/extreme-variance/hints.md

@@ -0,0 +1,2 @@
+- Check out [Covariance and Contravariance](https://peps.python.org/pep-0483/#covariance-and-contravariance)
+- A bytes object behaves like an immutable sequences of integers

challenges/extreme-variance/question.py

@@ -22,6 +22,10 @@ def g(a):
 g(l2)
 
 f(1)  # expect-type-error
-f("1")  # expect-type-error
+f("abc")  # expect-type-error
+g("abc")
+g(b"abc")
+g([1, "2"])
+g((1, "2", 3))
 g(1)  # expect-type-error
-g("1")
+g({1})  # expect-type-error

challenges/extreme-variance/solution.py

@@ -24,6 +24,10 @@ def g(a: Sequence[int | str]):
 g(l2)
 
 f(1)  # expect-type-error
-f("1")  # expect-type-error
+f("abc")  # expect-type-error
+g("abc")
+g(b"abc")
+g([1, "2"])
+g((1, "2", 3))
 g(1)  # expect-type-error
-g("1")
+g({1})  # expect-type-error