Sample tests have some wrong.

1. The edge test L..... shouldn't be LLLLLL.
2. The balance test input string length is 3002, but the except string length is 3000.

Are there any cases that take a long time to execute (javascript)?

In the basic tests, the longest execution time falls between 30 to 50 ms.

However, I still fail to pass the 12000ms limit.

Additionally, due to the timeout error, I am unable to print anything.

1. Does the lifespan apply only to the mature stage, excluding the piglet phase?
   If so, does that mean the total lifespan from birth to death is 17 and 18 days?
   If not, does that mean the initial pigs are actually 5 days old? Or are they 1 day old and already mature?
2. What is the priority to selecting couples? Older first? Younger first? Boar first? Sow first?
3. What happens if one member of a couple dies? Still need to waiting days? Or instantly can meet next mate?

It's weird to use pigs here.

If no existing species fits your need, you could simply create a new one.

Or just say these pigs are from another planet, so we won't use real life case to think about it.

Spent 2 hours for not reading properly XD

It's a bit late, but I'm sure someone else has faced this issue too.

This kata requires you to return a String.

I tried to clear up any confusion in the description, it was really hard for me to figure out what I was supposed to do.

Use console.log() to see the input.

Issue tag is for kata issue not your code issue,
you should choose Question to looking for help.

Your checking rules is not what description says, there just 4 rules and you have 5.

Fixed translation here. Need someone to approve.

It has already been approved.

If that, I'll prefer it to be a new kata. Otherwise thanks for replying.

I often forget about that ternary operator exists, and use if...else.

Approved by someone

ideally there should be some explanation in the initial code, yes. you can open a suggestion to request that.

Using enums is a great choice when they are supported.

But on Codewars, you don't get the exact definition of the enum, so you need to guess how to use it.

Is it really a good idea to go with that?