Lots of probing to improve initial algorithm in various ways: better runtime, less memory, possible flaws
Sigiloso
There's quite an extended back and forth in actual interviews for questions like this, so nothing quite like real practice. The Prepfully Pinterest Software Engineering Intern experts have actually worked in this role, so they're able to do an honest-to-God accurate mock, which really puts you through the paces. prepfully.com/practice-interviews