In an undirected graph, print the adjacent nodes for each node of the graph.

Input: Use file redirection to read from the file graph.txt

The first line of the input contains only one token, n - the number of nodes of an undirected graph; the nodes then are named 1,...,n.

Next, the boolean adjacency matrix is read in - line by line - n lines in total. The program should check that all diagonal elements are 0 (i.e. false) and that the matrix is symmetric; print an error message if this is not the case.

Output - For each node, print out the name of the adjacent nodes, one line for each node.

Use C++.