def test_subarray_sum():
"""Tests subarray_sum function """
assert [20, 3, 10] == subarray_sum([1, 4, 20, 3, 10, 5], 33)
assert [4, 0, 0, 3] == subarray_sum([1, 4, 0, 0, 3, 10, 5], 7)
assert [] == subarray_sum([1, 4], 0)
assert [2] == subarray_sum([2], 2)
assert [] == subarray_sum([2], 3)
def problem_50():
""" Attempt to solve the problem... """
primes = list(seive_generator(1000000))
best = (0, 0)
for prime in primes:
ans = subarray_sum(primes[:int(prime ** 0.5)], prime)
if len(ans) > best[1]:
best = (prime, len(ans))
return best[0]