That seems to be specific way of traversing Linked Lists (which ostensibly is different than all the other ways it has been done in textbooks, published code etc.) , not Linked Lists themselves. If you find a way of traversing a list in a way that has not been done before you can apply for a patent fort that technique. If i were to use that technique of traversing linked in a product that i sell, you could sue me. However, if came up with that particular, specific way of traversing a linked list in an interview, no patents are violated anywhere. That's just silly.
I. Software is mathematics.
II. Mathematics are not patentable.
>> Software is not patentable.
Pick a premise and argue against it. Or, don't bother: you and the US legal system are in an argument against reality. It's not a winnable argument, but sense can take a long time to percolate through obstinate stupidity.
i'm not arguing for or against patents on software, mathematics or otherwise. I'm just saying that answering an interview question about how a particular thing might be done is not in violation of any patent laws. Replace "method for traversing linked lists" with "a new technique for cutting wood using a new tool" if you feel so strongly about software patents.
