1. An undirected graph with n vertices has at most () edges.
A. n(n-1)/2
B. n(n-1)
C. n
D. 2n
查看答案
2. In a directed graph with n vertices, at least arcs ( ) are required to connect all vertices.
A. n
B. n-1
C. n+1
D. 2n
3. In an undirected graph, the sum of degrees of all vertices is equal to () times the number of edges.
A. 2
B. 1/2
C. 1
D. 4
4. In a directed graph, the sum of the in degrees of all vertices is equal to () times the sum of the out degrees of all vertices.
A. 1
B. 1/2
C. 1
D. 4
5. For an undirected graph represented by an adjacency list with n vertices and e edges, the storage space occupied is ().
A. n+2e
B. e
C. 2e
D. n+e