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> There are 'n' vertices and 0 edges of an undirected graph. What can be the maximum number of edges that we can draw such that the graph remains disconnected.
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I have made the solution that we can exclude one vertex and can find the maximum number of edges between n-1 vertices of undirected graph, so that the graph still remains disconnected.

which is n(n-1)/2 for n vertices and will be (n-1)(n-2)/2 for n-1 vertices.
 Can there be a better solution?