2. (25 pts) Give a big-O estimate for the number of operations, where an operation is a
comparison or a multiplication, used in this segment of an algorithm (ignoring comparisons
used to test the conditions in the for loops, where $a_1, a_2, \dots, a_n$ are positive real numbers).
$i := 1$
$t := 0$
$\text{while } i \le n$
$t := t + i$
$i := 2i$
3. (25 pts) Determine whether the given pair of directed graphs are isomorphic.
4. (25 pts) Find the number of vertices, the number of edges, and the degree of each vertex
in the given undirected graph.