Weak Password Hashing — The Salt Must Affect the Output

The password-hashing function below is supposed to combine a password with a per-user salt, but the salt is silently ignored.

The bug: without a salt actually mixed into the hash, two users with the same password get the exact same hash — letting an attacker with database access instantly spot duplicate passwords and use precomputed rainbow tables, defeating the entire purpose of salting.

Your task: fix solve(password, salt) so the returned hash genuinely depends on both password and salt — changing either one must change the output.