# smallest Bipartite Graph

Definition: A graph G is bipartite if its vertices can be partitioned into two sets V1 and V2 and every edge joins a vertex in V1 with a vertex in V2. Bipartite graphs can be characterized by all circuits in such graphs having even length (if there are no circuits, the graph is also bipartite), where the length of a circuit or path is the number of edges in it What is the smallest bipartite graph?:

• Well, if they're allowed to be empty, just take $V_1=V_2=\emptyset$ and the empty graph is bipartite. – YoTengoUnLCD Feb 6 '16 at 0:20