Write count_between(nums, lo, hi) returning how many values are in [lo, hi] (inclusive), using a boolean mask and sum.
count_between([1, 5, 10, 15], 5, 10) → 2
count_between([], 0, 1) → 0
Submit runs 3 tests, including hidden edge cases.
Each hint gives a little more help. Try on your own first.
Run your code to see the output here.