Submitting a more efficient solution to online coding test after deadline? [duplicate]

Question

I just had an online coding assessment for a job, that had many multiple choice questions and two coding challenges, all to be completed in 90 minutes.

I am confident about my multiple choice answers and knew that I got the correct solution to the first coding challenge.

I was also able to solve the second challenge, but the issue is that it did not pass all the test cases (only 3 out of 14) which was because my solution takes up a longer time than expected to solve the problem. I knew I had to optimize my algorithm more but ran out of time.

So, after having the assessment I emailed the employer thanking them about the opportunity and how I wished I had more time to optimize my solution.

I took the online assessment at midnight, optimized my code in the morning and got the optimal solution.

Questions: Is it advisable that I email the employer to tell them that I have come up with an optimal solution for problem number two? What impression will I make with the employer upon doing this? How should I tell them that I am sending them the solution/modification to my original answer without sounding annoying?

Answer 1

Is it advisable that I email the employer to tell them that I have come up with an optimize solution for problem number two?

It's almost certainly not going to do you any harm - but rather than just saying "I have come up with an optimize[d] solution", send them the code. It's always better to show what you can do rather than tell someone that you can do something without evidence.

How should I tell them that I am sending them the solution/modification to my original answer without being annoying?

Be humble. "Thanks for the test. I found it interesting but didn't have enough time to optimize the second part. I don't like leaving problems unfinished, so I had a go at this in my spare time - I've attached my effort.

Thanks,

Little Tiny Dev".

As an aside:

I took the online assessment at midnight

Unless you're truly a night owl, don't do that. You want to do be doing this sort of thing when you're at your absolute best, not as your body is starting to wind down at the end of the day.