Remove and Append in a Linked List

Implement a doubly linked list having all unique elements with the following operations. $I$ $x$ – Inserts element $x$ alternately at the head and at the end. $S$ $pos1$ $pos2$ – Shuffles the list by removing nodes from position $pos1$ to position $pos2$. Assume the head or first node is at position $1$, $pos1$ and $pos2$ are always valid and $pos1$ is always less than equals to $pos2$. This ope