What does 利口耳丝耳 and 利口丝久 mean?
I believe 利口 is the Chinese for:
Leet Code

[a] platform to help you enhance your skills, expand your knowledge and prepare for technical interviews.


and the rest are just numbers:

耳丝耳 = 242
丝久 = 49
斯尔 = 12
散灵思 = 304
丝丝久 = 449

Although there might be some mistakes in the numbers there.

If we take 利口散灵思 for example that gives us: LeetCode 304 which is a question about:

Range Sum Query 2D - Immutable（Python）


Now back to the question at hand:

Leetcode 22. Generate Parentheses
LeetCode 19. Remove Nth Node From End of List


p.s.: the offical name for Leet Code in Chinese seems to be:

力扣

maybe the alternative translation adds to the code.

Leet Code has a list of articles here ordered by number.