19: Remove Nth Node From End of List
The requirement for one-pass algorithm is misleading. True one-pass for this kind of problem is impossible (One-pass Algorithm).
One way is to iterate through the list, find it's length, then iterate again, and stop behind the node to be removed, and change references appropriately.
Another approach would be to maintain two pointers to the list, both having
distance between them. Continue iterating over the list, and updating pointers,
until the farther one reaches the end of the list. When this happens, the other
pointer will be at the node to be removed.