How to represent a strange graph in some data structure

Question

A simple way to represent a graph is with a data structure of the form:

{1:[2,3],
 2:[1,3],
 3:[1,2]}

Where the keys in this dictionary are nod

Answer 1

This could be represented by a directed graph.

Nodes in your graph could be represented as two nodes in the graph. Think of the nodes as representing locations on particular sides of a street -- the edges being like inbound and outbound lanes.