Let G be a simple undirected graph. Let TD be a depth first search tree of G. Let TB be a breadth first search tree of G. Consider the following statements. (I) No edge of G is a cross edge with respect to TD. (A cross edge in G is between two nodes neither of which is an ancestor of the other in TD .) (II) For every edge (u, v) of if u is at depth i and v is at depth j in TB , then |? − ?| = 1. Which of the statements above must necessarily be true?
Let G be a simple undirected graph. Let TD be a depth first search tree of G. Let TB be a breadth first search tree of G. Consider the following statements. (I) No edge of G is a cross edge with respect to TD. (A cross edge in G is between two nodes neither of which is an ancestor of the other in TD .) (II) For every edge (u, v) of if u is at depth i and v is at depth j in TB , then |? − ?| = 1. Which of the statements above must necessarily be true? Correct Answer I only
Undirected graph cant have cross edges in DFS forest. Hence statement 1 is TRUE.
Using triangle graph we can counter the second statement.
মোঃ আরিফুল ইসলাম
Feb 20, 2025