How can i write the code about undirected graph?

[trouble34]

i have an problem with a question.there is an undirected graph and below is a sample file:
3 7
5 24
12 45
...
Each line above specifies an edge. I want to convert this to adjacency-list in C++.And here are my questions:
Sparsity of the graph
Degree of a vertex
Max, min, and avg. degrees.
Shortest path between two vertices
Shortest path passing through a particular vertex
Average shortest path length.
Diameter of the graph.

I just want to understand how can i start to write these codes.I need the codes,but even if you cannot write all ,just give the ideas about how to implement them.Thank you:))))