SHA256 is a fixed circuit. It's a particularly weird thing to implement. Other than it being a bit long, it's not complex to implement, even on a calculator. I

SHA256 is a fixed circuit. It's a particularly weird thing to implement. Other than it being a bit long, it's not complex to implement, even on a calculator. If you want an example of something moderately complex but well defined, go implement a min-heap or some other basic algorithm.