Hi, i need to create a list of list in STL where each element can move from a given list level to the adjacent list.

i.e.

| -> x -> y -> z

| -> a -> b

can be modified to

| -> x -> y

| -> z -> a -> b

the idea is that element can jump back the head of each list and then acces the other adjacent list (below). Space is not an issue: I accept the cost of the back pointer. But operation should be done in O(1).

What is the best way to describe this in STL?