Give them a real world simple use case where they have code and they have to fix real world code by making the unit test pass.

Never in almost 30 years of coding have I had to invert a b-tree or do anything approaching what leetCode tests for.

Well actually I did have to DS type code when writing low level cross platform C in the late 90s without a library.

But how many people have to do that today?

And how is leetCode testing the best way when all it tests for is someone’s ability to memorize patterns they don’t use in the real world?