Fig. 12

Two shortest-path trees of node \(v_1\); the center nodes of theĀ (a) tree are \(v_2\) and \(v_3\) and the center nodes of theĀ (b) tree are \(v_2\) and \(v_4\)
Two shortest-path trees of node \(v_1\); the center nodes of theĀ (a) tree are \(v_2\) and \(v_3\) and the center nodes of theĀ (b) tree are \(v_2\) and \(v_4\)