graph_info - Print basic information about a graph
graph_info prints the number of nodes, number of edges, average
degree, and average squared degree of graph_in.
-(dash), read the edge list from STDIN.
The program prints on STDOUT a single line in the format:
N K avg_k avg_k2
N is the number of nodes,
K is the number of edges,
is the average degree, and
avg_k2 is the average squared degree of graph_in.
(c) Vincenzo 'KatolaZ' Nicosia 2009-2017