1. Insert a node at front
2. Insert a node at end
3. Insert a node after given node information
4. Delete a node at front
5. Delete a node at end
6. Delete a node by given node information
7. Display a LinkList
1. Insert a node at front
2. Insert a node at end
3. Insert a node left to given node information
4. Insert a node right to given node information
5. Delete a node at front
6. Delete a node at end
7. Delete a node left to given node information
8. Delete a node right to given node information
9. Display a LinkList