This was the second or third thing we learned in a basic data structures course; not so much for the utility of the list but to become familiar with the applica

This was the second or third thing we learned in a basic data structures course; not so much for the utility of the list but to become familiar with the application of XOR to pointer arithmetic. That professor (his name was Jorge Orejel) was probably the best I've had. He was a hardass but really taught the fundamentals well. The 3 classes I took from him had something like 80% attrition because the lazy people gave up. No I wasn't one of the lazy people :)