Alright, I made a solution that actually works!

The challenge was to make a stack with a findMin function that could give you the smallest value in the stack in constant time.

This doesn't do that, but it does average better than just looking through the stack (although the tree isn't balanced, maybe I should do that...)

tagging @LottieVixen, who told me about the problem
https://computerfairi.es/media/GurlBHQi8UNfw4n70oY