The Clever Korner
The problem index · 36 problems

You don't know what it's called. You know what's going wrong.

Nobody searches for “olla irrigation.” They search for my garden dries out while I'm at work. So this index is organised the way the problem actually arrives — and every answer comes with a grade, including the popular ones that don't hold up.

Missing one?

A problem nobody has written up is the next entry.

This index grows from real problems rather than from a list of clever tricks. If you searched for something and found nothing, that gap is the most useful thing you could tell us — and if you've solved something and can show the numbers, that's how an entry earns its grade.