This one has constant comlexity O(1), while an iterator will have at least linear complexity O(n).
While this doesn't make this automatically more efficient for small values, we can optimise this solution by using bit operation for deviding but the compiler already does that for us.
So that means this solutuon needs 4 arthmic operations to execute, while the iterator solution needs at least n arethmic operations, meaning that if n is bigger than 4 the iterator solution is already worse.

Damn man you are good

please use the spoiler flag when posting anything related to the solution

Rejected for lack of random tests to avoid accidental approval, after 15 months without answer. Please publish a new fork with correct tests.

Yup that one should be best practice

I feel this one more performant for very large n, under the assumption that sum() function for iterators goes through n elements.

Good use of bit shifting

This fork should solve all issues:

• Updated to latest Rust version
• Updated description to current version to avoid merge issues
• Updated Initial Solution so it now compiles straight away
• Made more obvious assertion messages
• Updated random tests:
• • Upped count to 100 tests
• • Made generation more efficient
• • Made empty inputs possible
• • Included other bracket types as stated in description

Please include true random tests, and not a bunch of shuffled fixed tests. Most likely the descrption has been updated since you published your translation, so it's probably more secure to publish a new fork grabbing the current description (the best solution would be to make description language agnostic to end with those endless merge conflicts).

Please use spoiler flag next time.